Methods and apparatus for an active convertor dolly

ABSTRACT

The disclosure is directed at an apparatus for an active converter dolly for use in a tractor-trailer configuration. In one aspect, the apparatus includes a system to connect a first trailer towed behind a towing vehicle to a second trailer. The apparatus further includes a kinetic energy recovery device for translating the mechanical motions or actions of the dolly into electricity or electrical energy so that this energy can be used to charge a battery or to power other functionality for either the dolly or the tractor-trailer. The active dolly may also operate to assist in shunting the tractor-trailer. The active dolly is operable in a number of modes to increase vehicle performance and efficiency.

RELATED APPLICATION DATA

The present application claims priority to non-provisional U.S. patentapplication Ser. No. 15/608,098, filed May 30, 2017, the entire contentsof which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates generally to the road transportation industry.More specifically, the disclosure is directed at a method and apparatusfor an active convertor dolly.

BACKGROUND

Transportation of goods across road networks is typically accomplishedby way of a transport truck to which a transport trailer is attached.The truck provides the engine and the trailer provides the cargo spaceto transport goods within. A recent trend in the transportation of goodsby road is the expansion of the size of transport trucks. This expansionis accomplished by both larger trucks and larger trailers. Fewer tripswith larger loads can be more efficient in certain circumstances. Oneway to achieve larger loads is to add a pup trailer, also called asecond trailer, behind the main trailer (also called a first trailer). Atransport trailer with the pup trailer may be called a transport trailertrain.

The typical equipment used to attach a pup trailer to a transporttrailer is called a converter dolly. Current convertor dollies arepassive and limited in their use and application. They provide a set ofwheels to support the front end of the pup (secondary) trailer and aconnector assembly for connecting to the rear end of the main (primary)trailer.

SUMMARY

The present disclosure describes a converter dolly apparatus with anelectrical kinetic energy recovery device for capturing braking energy.A number of applications are described, including regenerative brakingand active electrical motor control of the dolly wheels for improvingthe fuel economy of transport trucks.

In one aspect of the disclosure, there is provided an apparatus forreleasably coupling a second trailer to a first trailer that isreleasably coupled to a towing vehicle in a tractor-trailer vehicleconfiguration. The apparatus comprises a frame, a first trailerconnector assembly for releasably coupling the apparatus to the firsttrailer such that the apparatus translates with the first trailer; asecond trailer connector assembly for releasably coupling the apparatusto the second trailer such that the second trailer translates with theapparatus; a pair of wheels; and a kinetic energy recovery deviceadapted to recover energy from regenerative braking of at least onewheel of the at least one pair of wheels. The first trailer connectorassembly, the second trailer connector assembly, the at least one of thewheels, and the kinetic energy recovery device are cooperativelyconfigured such that while the first trailer translates with the towingvehicle, and the releasable coupling of the apparatus to the firsttrailer and to the second trailer is effected, braking by the towingvehicle is with effect that the kinetic energy recovery device convertskinetic energy generated by rotation of the at least one of the wheelsto electrical energy.

In another aspect, the releasable coupling of the apparatus to the firsttrailer via the first trailer connector assembly includes electricalconnection of the kinetic energy recovery device to the first trailerfor receiving vehicle data from the towing vehicle.

In another aspect, the releasable coupling of the apparatus to thesecond trailer via the second trailer connector assembly electricalconnection of the kinetic energy recovery device to the second trailerfor receiving second-trailer connection data.

(i) In another aspect the kinetic energy recovery device includes amotor-generator operably coupled to the at least one of the wheels,wherein the at least one motor-generator is operable in: a drive modefor applying a motive rotational force to the at least one wheel; and agenerator mode for applying a regenerative braking force to the at leastone wheel for converting the kinetic energy to the electrical energy,the regenerative braking force effecting deceleration of the at leastone wheel; and an energy storing device for storing the electricalenergy.

In another aspect, the kinetic energy recovery device includes acontroller operably coupled to the motor generator for selectivelyactivating the drive mode or the generator mode.

In another aspect, the at least one of the wheels, the motor-generator,and the controller are cooperatively configured such that while thefirst trailer is releasably coupled to the towing vehicle and translateswith the towing vehicle, and the releasable coupling of the apparatus tothe first trailer and to the second trailer is effected, acceleration ofthe towing vehicle effects activation of the drive mode of themotor-generator.

In another aspect, the at least one of the wheels, the at least onemotor-generator, and the controller are cooperatively configured suchthat while the first trailer is releasably coupled to the towing vehicleand translates with the towing vehicle, and the releasable coupling ofthe apparatus to the first trailer and to the second trailer iseffected, deceleration of the towing vehicle effects activation of thegenerator mode of the motor-generator.

In another aspect, a first wheel of the at least one pair of wheels isdisposed on a first side of a central longitudinal of the frame; and asecond wheel of the at least one pair of wheels is disposed on a second,opposite side of the central longitudinal axis of the frame; wherein thefirst wheel, the second wheel and the frame are cooperatively configuredsuch that the first wheel and the second wheel are disposed for rotationabout an axis transverse to, or substantially transverse to, the centrallongitudinal axis of the frame.

In another aspect, the apparatus further comprises an axle coupled tothe frame, wherein each wheel of the pair of wheels is, independently,mounted to the axle; and the motor-generator is operably coupled to theaxle such that the motive rotational force is transmitted to both wheelsby the axle when the motor-generator operates in the drive mode, and theregenerative braking force is applied to both wheels by the axle whenthe motor-generator operates in the generator mode.

In another aspect, the apparatus further comprises a first drive shaftcoupled to the frame wherein a first wheel of the pair of wheels isrotatably coupled to the first drive shaft such that the rotatablecoupling of the first wheel to the frame on the second side of thecentral longitudinal axis of the apparatus is effected; a second driveshaft coupled to the frame, wherein the second wheel of the pair ofwheels is rotatably coupled to the second drive shaft such that therotatable coupling of the second wheel to the frame on the second sideof the central longitudinal axis is effected; a first motor-generatoroperably coupled to the first drive shaft, wherein the firstmotor-generator is operable in: a drive mode for applying a motiverotational force to the first wheel; and a generator mode for applying aregenerative braking force to the first wheel for converting the kineticenergy to the electrical energy, the regenerative braking forceeffecting deceleration of the first wheel; and a second motor-generatoroperably coupled to the second drive shaft, wherein the secondmotor-generator is operable in: a drive mode for applying a motiverotational force to the second wheel; and a generator mode for applyinga regenerative braking force to the second wheel for converting thekinetic energy to the electrical energy, the regenerative braking forceeffecting deceleration of the second wheel.

In another aspect, the first motor-generator and the secondmotor-generator are independently controlled.

In another aspect, the first drive shaft and the second drive shaft areinterconnected by a differential.

In another aspect, the first and second wheels, the energy storingdevice, the first and second motor-generators, and the controller arecooperatively configured such that the first and second motor-generatorsare powered in the drive mode by the energy storing device.

In another aspect, there is provided an apparatus for releasablycoupling a second trailer to a first trailer that is releasably coupledto a towing vehicle in a tractor-trailer vehicle configuration, theapparatus comprising a frame; a first trailer connector assembly forreleasably coupling the apparatus to the first trailer such that theapparatus translates with the first trailer; a second trailer connectorassembly for releasably coupling the apparatus to the second trailersuch that the second trailer translates with the apparatus; a pair ofwheels rotatably coupled to the frame; a kinetic energy recovery deviceoperably coupled to at least one of the wheels for converting mechanicalenergy generated by rotation of the at least one of the wheels toelectrical energy; and an energy storing device electrically connectedto the kinetic energy recovery device for storing electrical energygenerated by the kinetic energy recovery device, wherein the firsttrailer connector assembly, the second trailer connector assembly, theat least one of the wheels, the kinetic energy recovery device, and theenergy-storing device are co-operatively configured such that while thefirst trailer translates with the towing vehicle and the releasablecoupling of the apparatus to the first trailer and to the second traileris effected, and the towing vehicle is decelerating, the kinetic energyrecovery device converts the mechanical energy to electrical energy,which electrical energy is stored on the energy storing device.

In another aspect, the kinetic energy recovery device comprises amotor-generator operably coupled to the at least one wheel and to theenergy storing device, wherein the motor-generator is operable in: adrive mode for applying a motive rotational force to the at least one ofthe wheels; and a generator mode for applying a regenerative brakingforce to the at least one of the wheels for converting mechanical energygenerated by rotation of the at least one of the wheels to electricalenergy wherein the generated electrical energy is stored on theenergy-storing device; and a controller for selectively activating thedrive mode or the generator mode of the motor-generator.

In another aspect, a corresponding motor-generator is operably coupledto each wheel in the pair of wheels.

In another aspect, each one of the wheels, independently, includes ahub; and the corresponding motor-generator for each wheel is disposedwithin the hub.

In another aspect, the apparatus further comprises a frame and at leastone axle coupled to the frame, wherein each wheel of the at least onepair of wheels is mounted to the at least one axle; and themotor-generator is operably coupled to the at least one axle such thatoperation of the motor-generator in the drive mode applies motiverotational force to both wheels in the at least one pair of wheels, andoperation of the motor-generator in the generator mode generateselectrical energy in response to a deceleration in rotation of bothwheels which electrical energy is stored on the energy-storing device.

In another aspect, the apparatus further comprises a frame; a firstdrive shaft coupled to the frame, wherein a first wheel is mounted oncoupled to the frame and connecting a first wheel of the at least onepair of wheels to the frame on a first side of the central longitudinalaxis of the apparatus; and a second drive shaft coupled to the frame andconnecting a second wheel of the at least one pair of wheels to theframe, wherein: the motor-generator is a first motor-generator operablycoupled to the first drive shaft, such that operation of themotor-generator in the drive mode is with effect that motive rotationalforce is applied to the first wheel, and operation of the firstmotor-generator in the generator mode generates electrical energy inresponse to a deceleration in rotation of the first wheel, whichelectrical energy is stored by the energy-storing device; the kineticenergy recovery device including a second motor-generator operablycoupled to the second drive shaft such that operation of the secondmotor-generator in the drive mode is with effect that motive rotationalforce is applied to the second wheel, and operation of the secondmotor-generator in the generator mode generates electrical energy inresponse to a deceleration in rotation of the second wheel, whichelectrical energy is stored by the energy-storing device.

In another aspect, the first motor-generator and the secondmotor-generator are independently controlled.

In another aspect, the first drive shaft and the second drive shaft areinterconnected by a differential.

In another aspect, the frame includes a tongue portion and a wheelsupporting portion, wherein: the at least one axle is coupled to thewheel supporting portion; and the first trailer connector assembly isdisposed at an end of the tongue portion.

In another aspect, the tongue portion defines an opening; and thecontroller and the energy storing device are disposed within theopening.

In another aspect, the motor-generator includes a motor-generatorreduction gear; and the motor-generator reduction gear is embeddedwithin the at least one axle.

In another aspect, the apparatus further comprises a coaster wheel forsupporting the apparatus when the releasable coupling of the firsttrailer to the apparatus by the first trailer connector assembly isun-coupled, and a steering mechanism, wherein the coaster wheel, thesteering mechanism, the at least one pair of wheels, the kinetic energyrecovery device, and the energy-storing device are co-operativelyconfigured such that while the releasable coupling of the first trailerto the apparatus is not effected and the releasable coupling of thesecond trailer to the apparatus is effected, and while electrical energyis stored on the energy storing device, the motor-generator is operablein the drive mode such that the second trailer translates with theapparatus.

In another aspect, the apparatus further comprises a steering device forreleasably coupling to the steering mechanism, for steering theapparatus and second trailer, wherein the steering device includes asteering column with a steering wheel.

In another aspect, the first trailer connector assembly includes a hitchassembly.

In another aspect, the second trailer connecting assembly includes afifth wheel assembly.

In another aspect, the second trailer connector assembly includes aspring suspension system for dampening displacement of the secondtrailer along an axis perpendicular to, or substantially perpendicularto, a central longitudinal axis of the apparatus.

In another aspect, the energy storing device includes one or morebatteries.

In another aspect, the energy storing device includes one or morebatteries and one or more capacitors.

In another aspect, the energy-storing device and the controller aredisposed intermediate the first trailer connector assembly and thesecond trailer connector assembly.

In another aspect, the energy-storing device and the controller aredisposed in a housing.

In another aspect, the housing includes an aerodynamic leading profilefor reducing drag on the apparatus in response to forward displacementof the tractor-trailer vehicle.

In another aspect, the apparatus further comprises a cooling systemdisposed within the housing for cooling the energy-storing device andthe controller.

In another aspect, the cooling system is a liquid-cooled cooling system.

In another aspect, the second trailer connector assembly includes asecond trailer support surface and the releasable coupling of theapparatus to the second trailer via the second trailer connectorassembly is with effect that the second trailer support surface isdisposed underneath the second trailer.

In another aspect, the first trailer connector assembly includes a fifthwheel assembly.

In another aspect, the first trailer connector assembly includes a hitchassembly and the releasable coupling of the apparatus to the firsttrailer is with effect that the apparatus is disposed behind the firsttrailer relative to a central longitudinal axis of the tractor-trailervehicle.

In another aspect, the housing is disposed such that the apparatus has acentre of gravity disposed below a central, midline axis of theapparatus.

In another aspect, the frame is a metal frame.

In another aspect, the frame includes a first material and a secondmaterial, wherein the first material is a metal material and the secondmaterial is a composite material having a weight that is less than theweight of the metal material such that the frame has a weight that isless than a weight of a frame having only the first, metal material forincreasing fuel efficiency of the tractor-trailer vehicle.

In another aspect, an apparatus is provided for releasably coupling asecond trailer to a first trailer that is releasably coupled to a towingvehicle in a tractor-trailer vehicle configuration, the apparatuscomprising a first trailer connector assembly for releasably couplingthe apparatus to the first trailer such that the apparatus translateswith the first trailer; a second trailer connector assembly forreleasably coupling the apparatus to the second trailer such that thesecond trailer translates with the apparatus; at least one pair ofwheels; a kinetic energy recovery device adapted to recover energy fromregenerative braking of the at least one pair of wheels; anenergy-storing device electrically connected to the kinetic energyrecovery device for storing the electrical energy generated by theregenerative braking; wherein the energy-storing device is disposedintermediate the first trailer connector assembly and the second trailerconnecting assembly.

In another aspect, the first trailer connector assembly, the secondtrailer connector assembly, the at least one pair of wheels, the kineticenergy recovery device and the energy storing device are cooperativelyconfigured such that while the releasable coupling of the apparatus tothe first trailer is effected and the releasable coupling of theapparatus to the second trailer is effected, the energy storing deviceis free of interference from the first trailer and the second trailer.

In another aspect, the kinetic energy recovery device includes at leastone motor-generator operably coupled to the at least one wheel, whereinthe at least one motor-generator is operable in:

(i) a drive mode for applying a motive rotational force to the at leastone wheel; and

(ii) a generator mode for applying a regenerative braking force to theat least one wheel for converting the kinetic energy to the electricalenergy, the generator mode effecting deceleration of the at least onewheel; and

a controller operably coupled to the at least one motor generator forselectively activating the drive mode or the generator mode, wherein thecontroller is disposed intermediate the first trailer connector assemblyand the second trailer connecting assembly proximal to the energystoring device such that while the releasable coupling of the apparatusto the first trailer is effected and the releasable coupling of theapparatus to the second trailer is effected, the controller is free ofinterference from the second trailer.

In another aspect, the energy storing device and the controller aredisposed in a housing.

In another aspect, the apparatus further comprises a frame having atongue portion and a wheel supporting portion, wherein: the firsttrailer connector assembly is disposed at a first end of the tongueportion and the wheel supporting portion extends from a second end ofthe tongue portion; the at least one pair of wheels is mounted to thewheel supporting portion such that a first wheel is disposed on a firstside of a central longitudinal axis of the frame and configured forrotation about an axis transverse to, or substantially transverse to,the central longitudinal axis of the frame, and a second wheel isdisposed on a second, opposite side of the central longitudinal axis andconfigured for rotation about and an axis transverse to, orsubstantially transverse to, the central longitudinal axis of the frame;the second trailer connecter assembly is supported by the wheelsupporting portion; and the tongue portion defines an opening, thehousing disposed within the opening and secured to the frame.

In another aspect, an apparatus is provided for releasably coupling asecond trailer to a first trailer that is releasably coupled to a towingvehicle in a tractor-trailer vehicle configuration, the apparatuscomprising a frame; a first trailer connector assembly disposed at afirst end of the frame for releasably coupling the apparatus to thefirst trailer such that the apparatus translates with the first trailer;a second trailer connector assembly for releasably coupling theapparatus to the second trailer such that the second trailer translateswith the apparatus; at least one pair of wheels; and a kinetic energyrecovery device adapted to recover energy from regenerative braking ofat least one wheel of the at least one pair of wheels, comprising atleast one motor-generator operably coupled to the at least one wheel,wherein the at least one motor-generator is operable in:

(i) a drive mode for applying motive rotational force to the at leastone wheel; and

(ii) a generator mode for converting the kinetic energy to theelectrical energy, the generator mode effecting deceleration of the atleast one wheel;

an energy storing device for storing the electrical energy; and acontroller operably coupled to the at least one motor generator forselectively activating the drive mode or the generator mode, wherein thefirst trailer connector assembly, the second trailer connector assembly,the at least one wheel, and the kinetic energy recovery device arecooperatively configured such that while the first trailer translateswith the towing vehicle, and the releasable coupling of the apparatus tothe first trailer and to the second trailer is effected, braking by thetowing vehicle is with effect that the kinetic energy recovery deviceconverts kinetic energy generated by rotation of the at least one wheelto electrical energy.

In another aspect, the apparatus further comprises a first drive shaftcoupled to the frame and connecting a first wheel of the at least onepair of wheels to the frame on a first side of the central longitudinalaxis of the apparatus; and a second drive shaft coupled to the frame andconnecting a second wheel of the at least one pair of wheels to theframe on a second, opposite side of the central longitudinal axis of theapparatus, wherein a first motor-generator is operably coupled to thefirst drive shaft, such that operation of the first motor-generator inthe drive mode is with effect that motive rotational force is applied tothe first wheel, and operation of the first motor-generator in thegenerator mode generates electrical energy in response to a decelerationof the first wheel, which electrical energy is stored by theenergy-storing device; and a second motor-generator, controlledindependently from the first motor-generator, is operably coupled to thesecond drive shaft such that operation of the second motor-generator inthe drive mode is with effect that motive rotational force is applied tothe second wheel, and operation of the second motor-generator in thegenerator mode generates electrical energy in response to a decelerationof the second wheel, which electrical energy is stored by theenergy-storing device.

In another aspect, the apparatus further comprises a first wheel speedsensor operably coupled to the first wheel or the first drive shaft forproviding first wheel speed data comprising a first wheel speed to thecontroller; and a second wheel speed sensor operably coupled to thesecond wheel or the second drive shaft for providing second wheel speeddata comprising a second wheel speed to the controller, wherein thecontroller is configured to detect a low-traction condition based on atleast the first wheel speed data and the second wheel speed data; andadjust motive rotational force applied to at least one of the firstwheel and the second wheel when a low-traction condition is detected.

In another aspect, the apparatus further comprises an axle lockingmechanism coupled to lock the rotation of the first drive shaft to therotation of the second drive shaft when the axle locking mechanism isactivated, wherein adjusting motive rotational force comprisesactivating the axle locking mechanism.

In another aspect, the first motor-generator and the secondmotor-generator are controlled independently.

In another aspect, detecting a low-traction condition comprisesdetecting that the difference between the first wheel speed and thesecond wheel speed is above a predetermined threshold.

In another aspect, adjusting motive rotational force comprisesincreasing the motive rotational force applied by the firstmotor-generator to the first wheel if the first wheel speed is lowerthan the second wheel speed and increasing the motive rotational forceapplied by the second motor-generator to the second wheel if the secondwheel speed is lower than the first wheel speed.

In another aspect, adjusting motive rotational force comprises reducingthe motive rotational force applied by the first motor-generator to thefirst wheel if the first wheel speed is higher than the second wheelspeed and reducing the motive rotational force applied by the secondmotor-generator to the second wheel if the second wheel speed is higherthan the first wheel speed.

In another aspect, the apparatus further comprises a gyroscope sensorattached to the frame for providing angular acceleration data to thecontroller and an accelerometer for providing linear acceleration datato the controller, wherein the low-traction condition is detected basedat least in part on the angular acceleration data.

In another aspect, detecting the low-traction condition comprisesdetecting that the apparatus is moving forward based on the linearacceleration data and detecting an increase in the angular accelerationof the apparatus about a vertical axis of the apparatus based on theangular acceleration data.

In another aspect, adjusting motive rotational force comprises adjustingat least one of the motive rotational force applied by the firstmotor-generator and the motive rotational force applied by the secondmotor-generator to create angular acceleration in the opposite directionof the detected increase in angular acceleration.

In another aspect, the controller is further configured to: detect thatthe low-traction condition is no longer present; and resume a baselineoperating mode.

In another aspect, the apparatus further comprises a communicationinterface for providing vehicle data from the towing vehicle to thecontroller.

In another aspect, the vehicle data comprises controller area networkbus data from the towing vehicle.

In another aspect, the communication interface comprises a wirelesscommunication interface.

In another aspect, the wireless communication interface is configured tocommunicate with an on-board diagnostics port of the tractor.

In another aspect, the vehicle data comprises: vehicle braking dataindicating the degree of braking applied by the driver of the tractor;and vehicle speed data indicating the speed of the tractor; and thecontroller is further configured to activate an electric-vehicle mode,comprising the drive mode of the motor-generator, in response todetecting: that a state of charge of the energy storing device is abovea charge threshold; that the speed of the tractor is below a speedthreshold; and that the degree of braking applied by the driver is belowa braking threshold.

In another aspect, the charge threshold is between 10% and 40% of a fullcharge level of the energy storing device.

In another aspect, the speed threshold is between 5 kilometers/hour and40 kilometers/hour.

In another aspect, the braking threshold is between 10% and 50% of afull brake activation level.

In another aspect, the amount of motive rotational force applied by theat least one motor-generator in electric-vehicle mode is based on thedegree of braking applied by the driver.

In another aspect, the controller is further configured to deactivateelectric-vehicle mode in response to detecting: that a state of chargeof the energy storing device is below the charge threshold; that thespeed of the tractor is above the speed threshold; or that the degree ofbraking applied by the driver is above the braking threshold.

In another aspect, the towing vehicle, the first trailer, and the secondtrailer collectively include a plurality of electrical systems; thereleasable coupling of the apparatus to the first trailer via the firsttrailer connector assembly includes electrical connection of the kineticenergy recovery device to the first trailer for providing power from theenergy storing device to one or more of the first trailer and the towingvehicle; the vehicle data comprises vehicle transmission data indicatingthe state of the transmission of the towing vehicle; and the controlleris further configured to activate an anti-idling mode in response todetecting a parked state of the towing vehicle based on at least thevehicle transmission data, the anti-idling mode comprising using theenergy storing device to power one or more electrical systems selectedfrom the plurality of electrical systems.

In another aspect, the towing vehicle has a manual transmission; thevehicle data further comprises parking brake data indicating the stateof a parking brake of the towing vehicle; and the parked state isdetected based on at least vehicle transmission data indicating that thetransmission is in a manual state and parking brake data indicating thatthe parking brake is in an engaged state.

In another aspect, the plurality of electrical systems comprises aclimate-control system of one or more of the second trailer, the firsttrailer, and the towing vehicle; and the anti-idling mode comprisesusing the energy storing device to power the climate-control system.

In another aspect, activating the anti-idling mode further comprisessending an engine deactivation control signal to the towing vehicle.

In another aspect, the engine deactivation control signal is sent viathe electrical connection.

In another aspect, the communication interface is further configured tosend data from the controller to the towing vehicle and the enginedeactivation control signal is sent via the communication interface.

In another aspect, the releasable coupling of the apparatus to the firsttrailer via the first trailer connector assembly includes electricalconnection of the kinetic energy recovery device to the first trailerfor providing power from the energy storing device to one or more of thefirst trailer and the towing vehicle; and the controller is configuredto cause the kinetic energy recovery device to transmit stored energyfrom the energy storing device via the electrical connection tojumpstart a towing vehicle battery.

In another aspect, the controller further is configured to detect abackup jack-knifing condition based on at least the first wheel speeddata and the second wheel speed data; and adjust the speed of at leastone of the first wheel and the second wheel when a backup jack-knifingcondition is detected.

In another aspect, detecting a backup jack-knifing condition comprisesdetecting that: the first wheel and the second wheel are both rotatingbackward; and the difference between the first wheel speed and thesecond wheel speed is above a predetermined threshold.

In another aspect, adjusting the speed of at least one of the firstwheel and the second wheel comprises increasing the motive rotationalforce applied by the first motor-generator to the first wheel if thefirst wheel speed is lower than the second wheel speed and increasingthe motive rotational force applied by the second motor-generator to thesecond wheel if the second wheel speed is lower than the first wheelspeed.

In another aspect, adjusting the speed of at least one of the firstwheel and the second wheel comprises using the kinetic energy recoverydevice to apply regenerative braking: to the first wheel if the firstwheel speed is higher than the second wheel speed; and to the secondwheel if the second wheel speed is higher than the first wheel speed.

In another aspect, the apparatus further comprises a gyroscope sensorattached to the frame for providing angular acceleration data to thecontroller; and an accelerometer for providing linear acceleration datato the controller, wherein the backup jack-knifing condition is detectedbased at least in part on the angular acceleration data.

In another aspect, detecting the backup jack-knifing conditioncomprises: detecting that the apparatus is moving backward based on thelinear acceleration data; and detecting an increase in the angularacceleration of the apparatus about a vertical axis of the apparatusbased on the angular acceleration data.

In accordance with other aspects of the present disclosure, there areprovided methods of controlling a dolly apparatus as described above andherein.

In a further aspect, there is provided a method for providing stabilityassistance to a converter dolly towing a second trailer behind a firsttrailer, the first trailer being towed by a towing vehicle, theconverter dolly comprising at least one axle having at least a firstwheel on a left side of the converter dolly and a second wheel on theright side of the converter dolly, the first wheel being operablycoupled to a first motor-generator, the left second being operablycoupled to a second motor-generator, such that the first motor-generatorand second motor-generator are each operable in a drive mode forapplying a motive rotational force to the first or second wheelrespectively, and a generator mode for applying a regenerative brakingforce to the first or second wheel respectively for converting thekinetic energy to the electrical energy, the regenerative braking forceeffecting deceleration of the first or second wheel respectively, themethod comprising: detecting a low-traction condition based on at leasta rotational speed of the first wheel and a rotational speed of thesecond wheel; and adjusting one or more of the motive rotational forceand the regenerative braking force applied to at least one of the firstwheel and the second wheel when a low-traction condition is detected.

In a further aspect, there is provided a method for imparting forwardmotion a tractor-trailer vehicle using a converter dolly towing a secondtrailer of the tractor-trailer vehicle behind a first trailer of thetractor-trailer vehicle, the first trailer being towed by a towingvehicle, the converter dolly comprising at least one axle having atleast a first wheel on a left side of the converter dolly and a secondwheel on the right side of the converter dolly, the first wheel andsecond wheel being operably coupled to at least one motor-generator,such that the at least one motor-generator is operable in a drive modefor applying a motive rotational force to at least one of the firstwheel and second wheel, and an energy storing device used to provideelectrical power to the motor-generator in drive mode, the methodcomprising receiving at the converter dolly vehicle data from the towingvehicle, the vehicle data comprising braking data indicating the degreeof braking applied by the driver of the towing vehicle; and vehiclespeed data indicating the speed of the towing vehicle, and activatingthe drive mode of the at least one motor-generator in response todetecting that a state of charge of the energy storing device is above acharge threshold, that the speed of the towing vehicle is below a speedthreshold, and that the degree of braking applied by the driver of thetowing vehicle is below a braking threshold.

In a further aspect, there is provided a method for powering one or moreelectrical systems of a tractor-trailer vehicle using a converter dollytowing a second trailer of the tractor-trailer vehicle behind a firsttrailer of the tractor-trailer vehicle, the first trailer being towed bya towing vehicle, the converter dolly comprising an energy storingdevice, the method comprising: receiving vehicle data at the converterdolly comprising vehicle transmission data indicating the state of thetransmission of the towing vehicle; and activating an anti-idling modeof the converter dolly in response to detecting a parked state of thetowing vehicle based on at least the vehicle transmission data, whereinthe anti-idling mode comprises using the energy storing device to powerat least one of the one or more electrical systems.

In a further aspect, there is provided a method for providing backupassistance to a converter dolly towing a second trailer behind a firsttrailer, the first trailer being towed by a towing vehicle, theconverter dolly comprising at least one axle having at least a firstwheel on a left side of the converter dolly and a second wheel on theright side of the converter dolly, the first wheel being operablycoupled to a first motor-generator, the left second being operablycoupled to a second motor-generator, such that the first motor-generatorand second motor-generator are each operable in: a drive mode forapplying a motive rotational force to the first or second wheelrespectively; and a generator mode for applying a regenerative brakingforce to the first or second wheel respectively for converting thekinetic energy to the electrical energy, the regenerative braking forceeffecting deceleration of the first or second wheel respectively, themethod comprising: detecting a backup jack-knifing condition based on atleast a rotational speed of the first wheel and a rotational speed ofthe second wheel; and adjusting one or more of the motive rotationalforce and the regenerative braking force applied to at least one of thefirst wheel and the second wheel when a backup jack-knifing condition isdetected.

In a further aspect, there is provided a method for imparting forwardmotion a tractor-trailer vehicle using a converter dolly towing a secondtrailer of the tractor-trailer vehicle behind a first trailer of thetractor-trailer vehicle, the first trailer being towed by a towingvehicle, the converter dolly comprising: at least one axle having atleast a first wheel on a left side of the converter dolly and a secondwheel on the right side of the converter dolly, the first wheel andsecond wheel being operably coupled to at least one motor-generator,such that the at least one motor-generator is operable in: a drive modefor applying a motive rotational force to at least one of the firstwheel and second wheel; and a generator mode for converting kineticenergy to electrical energy, the generator mode effecting decelerationof at least one of the first wheel and second wheel, the methodcomprising: activating the drive mode of the at least onemotor-generator in response to detecting acceleration of the firsttrailer relative to the second trailer; and activating the generatormode of the at least one motor-generator in response to detectingdeceleration of the first trailer relative to the second trailer.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the methodcomprising: measuring a speed of the first wheel; measuring a speed ofthe second wheel; detecting a low-traction condition based on at leastthe speed of the first wheel data and the speed of the second wheel; andadjusting motive rotational force applied to at least one of the firstwheel and the second wheel when a low-traction condition is detected.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the dolly apparatushaving a kinetic energy recovery device that stores energy in an energystoring device during braking of the towing vehicle, the methodcomprising: determining a degree of braking applied by the towingvehicle; determining a speed of the towing vehicle; determining a stateof charge of an energy storing device of the apparatus; activate anelectric-vehicle mode of the apparatus in response to determining that astate of charge of the energy storing device is above a chargethreshold, he speed of the towing vehicle is below a speed threshold,the degree of braking applied by the driver is below a brakingthreshold, wherein the electric-vehicle mode comprises driving the dollyapparatus using the energy storing device.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the dolly apparatushaving a kinetic energy recovery device that stores energy in an energystoring device during braking of the towing vehicle, the methodcomprising: determining when the towing vehicle has been stopped for atleast a predetermined amount of time or when the towing vehicle is aparked state; activating an anti-idling mode in response to determiningthat the towing vehicle has been stopped for at least the predeterminedamount of time, that the towing vehicle is a parked state or both,wherein the anti-idling mode comprises powering one or more electricalsystems of the towing vehicle, the first trailer and/or the secondtrailer using the energy storing device.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the dolly apparatushaving a kinetic energy recovery device that stores energy in an energystoring device during braking of the towing vehicle, the methodcomprising: detecting a jumpstart condition of the dolly apparatus; andoperating the dolly apparatus to transmit stored energy from the energystoring device via an electrical connection a towing vehicle battery tojumpstart towing vehicle in response to detecting a jumpstart conditionof the dolly apparatus.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the methodcomprising: measuring a speed of the first wheel; measuring a speed ofthe second wheel; detecting a backup jack-knifing condition based on atleast the speed of the first wheel data and the speed of the secondwheel; and detect a based on at least the first wheel speed data and thesecond wheel speed data; and adjust the speed of at least one of thefirst wheel and the second wheel when a backup jack-knifing condition isdetected.

In a further aspect, there is provided a method of operating a dollyapparatus for releasably coupling a second trailer to a first trailerthat is releasably coupled to a towing vehicle in a tractor-trailervehicle configuration, the dolly apparatus having at least one pair ofwheels comprising a first wheel and a second wheel, the methodcomprising: measuring acceleration or deceleration of the first trailerrelative to the second trailer; operating at least one motor-generatorof the dolly apparatus in a drive mode in response to acceleration ofthe first trailer relative to the second trailer; and operating the atleast one motor-generator of the dolly apparatus in response todeceleration of the first trailer relative to the second trailer.

In accordance with further aspects of the present disclosure, there isprovided a non-transitory machine readable medium having tangibly storedthereon executable instructions for execution by a processor of acontroller of a dolly apparatus. The executable instructions, whenexecuted by the controller, cause the controller to perform the methodsdescribed above and herein, and cause the dolly apparatus to behave asdescribed above and herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made by way of example only to preferredembodiments of the disclosure by reference to the following drawings inwhich:

FIG. 1 is a side view of a tractor-trailer including an active converterdolly;

FIG. 2a is a perspective view of another embodiment of an activeconverter dolly;

FIG. 2b is a schematic diagram of one embodiment of a kinetic energyrecovery device for an active converter dolly;

FIG. 3 is a perspective view of the active converter dolly;

FIG. 4 is a perspective view of a battery enclosure of the activeconverter dolly;

FIG. 5a is a schematic view of an active converter dolly control system;

FIG. 5b is a flowchart outlining one embodiment of controlling an activeconverter dolly;

FIG. 5c is a flowchart outlining one embodiment of transmitting signalsfrom the converter dolly control system;

FIG. 6 is a schematic diagram of another embodiment of an activeconverter dolly for use with a tractor-trailer;

FIG. 7 is a chart outlining motor motive rotational force vs. throttle;

FIG. 8 is a chart outlining showing regenerative and friction brakemotive rotational force blending;

FIG. 9a is a chart outlining engine motive rotational force vs enginespeed for one active converter dolly operational mode;

FIG. 9b is a chart outlining engine motive rotational force vs enginespeed for a second active converter dolly operational mode;

FIG. 10 is a schematic diagram of another embodiment of a kinetic energyrecovery device;

FIG. 11 is a schematic diagram of a further embodiment of a kineticenergy recovery device;

FIG. 12 is a schematic diagram of a steering mechanism for use with anactive converter dolly apparatus;

FIGS. 13a and 13b are charts outlining turning radius with respect todifferent active converter dolly apparatus configurations;

FIG. 14 is a perspective view of another embodiment of an activeconverter dolly apparatus;

FIG. 15 is a simplified partial rear view of an active converter dollyapparatus with an in-wheel motor configuration;

FIG. 16 is a simplified partial rear view of an active converter dollyapparatus with a differential configuration;

FIG. 17 is a flowchart showing the operation of an example controller ofan active converter dolly apparatus operating in a stability-assistancemode;

FIG. 18 is a flowchart showing the operation of an example controller ofan active converter dolly apparatus configured with an electric-vehiclemode;

FIG. 19 is a flowchart showing the operation of an example controller ofan active converter dolly apparatus configured with an anti-idling mode;and

FIG. 20 is a flowchart showing the operation of an example controller ofan active converter dolly apparatus operating in a backup-assistancemode.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The disclosure is directed at an active converter dolly apparatus foruse in a tractor-trailer configuration. More specifically, withreference now to FIGS. 1-20, there is disclosed an apparatus forreleasably coupling a second trailer to a first trailer that isreleasably coupled to a tractor or towing vehicle in a tractor-trailervehicle configuration.

In one embodiment, the apparatus includes a system to connect a towingvehicle to a trailer. The apparatus further includes a kinetic energyrecovery device for translating the mechanical motions or actions of thedolly into electricity or electrical energy so that this energy can beused to charge an energy storing device such as a battery or to powerother functionality for either the dolly or the tractor-trailer.

With reference to FIG. 1, a schematic diagram of a tractor-trailervehicle configuration incorporating an example embodiment of an activeconverter dolly apparatus 14 according to the present disclosure isshown.

The tractor-trailer 10 includes a towing vehicle 13, such as a tractor,cab or truck that pulls a pair of trailers 12 (seen as a primary orfirst trailer 12 a and a secondary or second trailer 12 b) that areconnected to each other via an active convertor dolly apparatus 14. Theactive convertor dolly apparatus 14 connects the two trailers 12 a and12 b together such that they move with respect to each other when thetowing vehicle 13 is in motion. While only a pair of trailers 12 isshown, it will be understood that more than one active converter dollyapparatus 14 may be used in combination with additional trailers ininstances when a tractor-trailer configuration having more than twotrailers is desired. Accordingly, the active converter dolly apparatus14 disclosed in the subject application is not intended to be limited touse in a tractor-trailer configuration having only primary and secondarytrailers.

As shown in FIG. 1, the primary and secondary trailers 12 a, 12 b areconnected to each other via the active convertor dolly apparatus 14. Theactive convertor dolly apparatus 14 connects the two trailers 12 a and12 b such that they move together with the towing vehicle 13 when thetowing vehicle 13 is in motion. In some embodiments, for example, theapparatus 14 releasably couples the second trailer 12 b to the firsttrailer 12 a, which is releasably coupled to the towing vehicle 13, suchthat while the first trailer 12 a is releasably coupled to the towingvehicle 13 and the towing vehicle 13 is in motion, the apparatus 14translates with the first trailer 12 a and the second trailer 12 btranslates with the apparatus 14, the apparatus 14, the first trailer 12a, the second trailer 12 b and the towing vehicle 13 therefore togetherforming the tractor-trailer vehicle configuration.

The towing vehicle 13 (sometimes referred to as a prime mover ortraction unit) is generally in the form of a heavy-duty towing vehiclehaving a heavy-duty towing engine that provides motive power for haulinga load. In the subject example embodiment, the towing vehicle 13 has acab portion 13 a and a flatbed portion 13 b that extends rearwardly fromthe cab portion 13 a. The cab portion 13 a includes an enginecompartment 13 c and a driver compartment 13 d. A front axle 13 e islocated under the engine compartment 13 c and one or more rear axles 13f are located under the flatbed portion 13 b of the towing vehicle 13.While in the subject example embodiment the towing vehicle 13 is shownas having only three axles, it will be understood that the actual numberaxles can vary depending on the actual size of the towing vehicle 13 andthe various sizes/types of loads that the towing vehicle 13 isconfigured for or intended to pull.

In some embodiments, for example, one or more axles on the towingvehicle 13 may be steering axles and one or more axles are driven axlesfor transmitting motive power from the engine to the wheels 16.Un-driven axles are those that do not receive motive power from theengine but that rotate as a result of the motion induced by the drivenaxles. In some embodiments, for example, the steering axle(s) may alsobe driven. In some embodiments, for example, an un-driven rear axle canbe raised such that the wheels mounted thereon are no longer in contactwith the ground or roadway in instances when the towing vehicle 13 islightly loaded or is not coupled to a trailer so as to save wear on thetires/wheels and/or increase traction on the wheels/tires associatedwith the driven axle(s).

Trailers 12 a, 12 b typically have no front axle and one or moreun-driven rear axles 112. In some embodiments, for example, the rearaxles 112 of trailers 12 a, 12 b are fixed axles and, in some exampleembodiments, the rear axles 112 may be part of a slider unit (not shown)that is mounted underneath the trailer 12 a, 12 b which allows the rearaxles 112 to be moved forward or backward, in accordance with principlesknown in the art, depending on the load being carried by the trailer 12.

In the subject example embodiment, the primary trailer or first trailer12 a is supported by the flatbed portion 13 b of the towing vehicle 13.In some embodiments, for example, in order to couple the first trailer12 a to the towing vehicle 13, the flatbed portion 13 b is provided witha coupling plate 15, commonly referred to as a fifth wheel coupling,configured for receiving and coupling with a corresponding locking pin,or kingpin, (not shown) that extends from underneath the first trailer12 b which is received within a corresponding slot formed in thecoupling plate 15, the first trailer 12 b resting and pivoting on thecoupling plate 15 about the locking pin. While a fifth wheel couplinghas been described in connection with the coupling of the first trailerto the towing vehicle 13 it will be understood that various othercouplings may be used provided the coupling between the towing vehicle13 and the first trailer 12 a is such that the first trailer translateswith the towing vehicle 13 when the towing vehicle 13 is in motion andcan pivot relative to the towing vehicle 13 for maneuverability. Thecoupling of the first trailer 12 a to the towing vehicle 13 alsoincludes the coupling of at least brake lines to transmit braking forcesto the wheels 16 of the trailer 12 a when the driver applies the tractorbrakes. The coupling of the first trailer 12 a to the towing vehicle 13also includes the coupling of electrical cable to ensure an electricalconnection between the tractor and the first trailer 12 a for properoperation of tail lights and any other required auxiliary devices orsystems associated with the first trailer 12 a.

In the subject example embodiment, the second trailer 12 b is coupled tothe first trailer 12 a by way of the active converter dolly or apparatus14. Accordingly, the active converter dolly or apparatus 14 includes atleast one pair of wheels 22 that act as the front axle of the secondtrailer 12 b and also includes a first trailer connector assembly 7 forreleasably coupling the apparatus 14 to the first trailer 12 a such thatthe apparatus 14 translates with the first trailer 12 a. A secondtrailer connector assembly 6 is provided for releasably coupling theapparatus 14 to the second trailer 12 b such that the second trailer 12b translates with the apparatus 14 with both the first trailer 12 a andthe second trailer 12 b being towed by the towing vehicle 13. Thecoupling of the second trailer 12 b within the tractor-trailer vehicleconfiguration also includes the coupling of brake lines and electricalcables to ensure proper operation of the tractor trailer vehicle 10. Asset out above, the apparatus 14 is intended to act as the front axle ofthe secondary trailer 12 b with only a portion of the apparatus 14extending underneath the secondary trailer 12 b such that there is apartial overlap of the trailer 12 b with respect to the apparatus 14. Insome embodiments, for example, the second trailer connector assembly 6includes a second trailer support surface and the releasable coupling ofthe apparatus 14 to the second trailer via the second trailer connectorassembly 6 is with effect that the second trailer support surface isdisposed underneath the second trailer 12 b. In some embodiments, forexample, the overlap between the secondary trailer 12 b and theapparatus 14 is less than 75% of the length of the secondary trailer 12b. In some embodiments, for example, the overlap between the secondarytrailer 12 b and the apparatus 14 is less than 50% of the length of thesecondary trailer 12 b. In some embodiments, for example, the overlapbetween the secondary trailer 12 b and the apparatus 14 is less than 25%of the length of the secondary trailer 12 b. Different embodiments ofthe apparatus 14 may have different maximum lengths when measured alongan axis of the apparatus 14 that is parallel to its central longitudinalaxis. In some embodiments, the maximum length is 15 feet. In otherembodiments, the maximum length is 12.5 feet. In other embodiments, themaximum length is 10 feet.

In some embodiments, for example, the active converter dolly orapparatus 14 defines a footprint having an area that is less than 50% ofan area defined by an undersurface of the secondary trailer 12 b. Insome embodiments, for example, the apparatus defines a footprint havingan area less than or equal to 50 ft².

In the subject example embodiment, the active converter dolly apparatus14 includes a kinetic energy recovery device 30 that is adapted torecover energy from regenerative braking of at least one wheel of the atleast one pair of wheels 22 wherein the first trailer connector assembly7, the second trailer connector assembly 6, the at least one wheel 22,and the kinetic energy recovery device 30 are cooperatively configuredsuch that while the first trailer 12 a translates with the towingvehicle 13, and the releasable coupling of the apparatus 14 to the firsttrailer 12 a and to the second trailer 12 b is effected, braking by thetowing vehicle 13 is with effect that the kinetic energy recovery device30 converts kinetic energy generated by rotation of the at least onewheel 22 to electrical energy. In some embodiments, for example, thefirst trailer connector assembly 7, the second trailer connectorassembly 6, the at least one wheel 22, the kinetic energy recoverydevice 30 and the energy storing device 32 are cooperatively configuredsuch that while the first trailer 12 a translates with the towingvehicle 13, and the releasable coupling of the apparatus 14 to the firsttrailer 12 a and to the second trailer 12 b is effected, and the towingvehicle 13 is decelerating, the kinetic energy recovery device 30converts the mechanical energy to electrical energy, which electricalenergy is stored on the energy storing device 32.

Regenerative braking, in general, is an energy recovery mechanism whenthe mechanical or kinetic energy generated by the rotation of the wheelsis recovered or converted into another usable form by applying aregenerative braking force to the wheels, the regenerative braking forceeffectively slowing down or causing a deceleration in the rotation ofthe wheels. More specifically, in systems incorporating regenerativebraking, an electric motor is used as an electric generator by operatingthe electric motor in reverse and is therefore often referred to as amotor-generator. The kinetic energy generated by the rotating wheels istransformed into electrical energy by the generator, which electricenergy is subsequently stored by an energy storing device 32 such as,for example, a battery. In some embodiments, for example, the energystoring device 32 includes one or more batteries and one or morecapacitors. The energy stored on the energy storing device can then beused for other applications.

In some embodiments, for example, the kinetic energy recovery device 30is a charge-generating system for translating mechanical motionexperienced by the apparatus 14 into an electric charge which allows theapparatus 14 to be used for other applications, as set out in moredetail below. In some embodiments, the electric charge can be used tocharge a battery or other energy storing device. In some embodiments,the electric charge may be used to power auxiliary devices likerefrigeration, an HVAC unit, or other climate control system mounted tothe tractor-trailer 10 as part of, either, the towing vehicle 13, firsttrailer 12 a, or second trailer 12 b. In some embodiments, the chargedbattery can be used to jumpstart a dead truck battery or to supply powerto accessories when the engine of the towing vehicle 13 is off. In someembodiments, the charged battery can be used to provide motiverotational force to the dolly's wheel through one or moremotor-generators.

In some embodiments, the controller is configured to detect a jumpstartcondition of the dolly apparatus 14. The jumpstart condition may be, forexample, a condition/state of an interrupt, a presence of an electricalconnection between the energy storing device 32 and a towing vehiclebattery, an operating condition of the controller (e.g., softwaresetting or the like), or a combination thereof. The dolly apparatus 14may be operated to transmit stored energy from the energy storing devicevia an electrical connection a towing vehicle battery to jumpstarttowing vehicle in response to detecting a jumpstart condition of thedolly apparatus 14.

In some embodiments, for example, the active convertor dolly apparatus14 may be configured to generate charge from other wheels and axleswithin the tractor-trailer vehicle 10, such as in a series or parallelimplementation, to charge the energy-storing device or battery.

In some embodiments, for example, the active convertor dolly apparatus14 is a through-the-road (TTR) hybrid vehicle as the apparatus 14 isconfigured to operate independently from the other axles of the trailers12 of the tractor-trailer vehicle 10 as will be described in furtherdetail below.

Turning to FIG. 2a , a perspective view of one example embodiment of anactive convertor dolly apparatus 14 is shown.

In this example embodiment, the active converter dolly apparatus 14includes a frame 24 including a wheel supporting portion, or second end,9 along with a tongue portion, or first end 8. The frame 24 can bemanufactured from different materials such as, but not limited to, highstrength steel, carbon fibre, aluminum, or other materials. As will beunderstood, the apparatus 14 does not have to be made entirely from onematerial and may be a combination of at least two different materials.As will be discussed in more detail below, the lightweight nature of thecomposite materials may also provide a benefit or advantage in terms offuel savings. In some embodiments, for example, the frame 24 is madefrom lightweight composites in combination with metal components whenrequired for strength or reinforcement purposes. Accordingly, in someembodiments, for example the frame 24 includes only a first materialwherein the first material is a metal material. In other embodiments,for example, the frame 24 includes a first material and a secondmaterial, wherein the first material is a metal material and the secondmaterial is a composite material having a weight that is less than theweight of the metal material such that the frame 24 has an overallweight that is less than an overall weight of a frame having only thefirst, metal material, the reduction in overall weight of the framecontributing to an increase fuel efficiency of the tractor-trailervehicle.

A first trailer connector assembly 7, which in the current embodimentcan be seen as a hitch 26, forms part of a tongue portion located at afirst end 8 of the frame 24 for connecting the converter dolly apparatus14 to the first trailer 12 a. The connection between the first trailer12 a and the converter dolly apparatus 14 will be well understood by oneskilled in the art. Although not shown, the first end 8 of the frame 24may also include safety chains and at least one electrical connection72, such as a wiring harness connection for enabling or securing thefirst trailer 12 a to the apparatus 14. The electrical connection 72 iscapable of delivering power from the trailer 12 a to the apparatus 14,and in some embodiments for providing power and/or data signals from theapparatus 14 to the first trailer 12 a. This electrical communicationmay extend through the first trailer 12 a to the towing vehicle 13, andit may be mediated at one or more points by further converters ortransformers, such as a DC-DC (direct current-direct current) converteror transformer for stepping down the high-voltage power stored in theenergy storage device of the apparatus 14 to the low-voltage electricalsystems of the towing vehicle 13. In some embodiments, the electricalconnection 72 includes electrical connection of the kinetic energyrecovery device 30 to the first trailer 12 b for receiving vehicle datafrom the towing vehicle 13.

In some embodiments, a support leg or support apparatus 27 is alsoattached to the frame 24 at the first end 8. In some embodiments, forexample, the support leg or apparatus 27 includes a coaster wheel.

The apparatus 14 has a second end 9 at the rear of the frame 24. Theframe 24 includes at least one pair of wheels 22 rotatably mounted tothe frame 24. For each one of the at least one pair of wheels 22, one ofthe wheels of the pair of wheels 22 is mounted on one side of the frame24 and the other one of wheels of the pair of wheels 22 is mounted to asecond opposite side of the frame 24. Each one of the wheels 22,independently, is disposed on opposite sides of a central longitudinalaxis of the apparatus 14 (i.e. from front first portion 8 to rear secondportion 9) and configured for rotation about an axis transverse to, orsubstantially transverse to, the central longitudinal axis of theapparatus (such as the axis from the left side to the right side of theframe 24). In the illustrated embodiment, the wheel pairs includes twowheels 22 to improve the load bearing capacity of the active converterapparatus 14.

In some embodiments, for at least one (for example, each one) of the atleast one pair of wheels 22, the wheels are mounted to an axle. In someembodiments, the axle is rotatably coupled to the frame 24. In someembodiments, for example, the axle is a single solid shaft (e.g.driveshaft) and each one of the wheels 22 of the pair, independently, isrotatably coupled to the same shaft, such that the axle includes, or isdefined by, the single solid shaft, and the single solid shaft is drivenby a motor. In some embodiments, for example, each one of the wheels 22of the pair, independently, is coupled to a respective shaft (e.g.driveshaft), such that one of the wheels of the pair is rotatablycoupled to a first driveshaft and the second one of the wheels of thepair is rotatably coupled to a second driveshaft, and the first andsecond driveshafts are coupled to each other via a differential, suchthat the axle includes, or is defined by, the first driveshaft, thesecond driveshaft, and the differential. In some embodiments, for atleast one (for example, each one) of the at least one pair of wheels 22,each one of the wheels of the pair, independently, is mounted to theframe 24 via a non-rotating shaft and is driven by a respectivedriveshaft (and each one of the wheels of the pair is coupled to its ownelectric motor-generator wheel assembly via its own driveshaft). In thisrespect, a first wheel on the left side of the frame 24 may be connectedto a first driveshaft 110, and a second wheel on the right side of theframe 24 may be connected to a second driveshaft 111, and there is anabsence of interconnection between the first and second driveshafts 110,111, and such that such that the axle includes, or is defined by, theindependent first and second driveshafts 110, 111. In some embodiments,each one of the wheels of the pair, independently, is mounted to theframe 24 via a non-rotational shaft and is coupled to its own electricmotor-generator wheel assembly (e.g. via a driveshaft), such that theaxle includes, or is defined by, the non-rotational shaft.

In the illustrated embodiment of FIG. 2a , a secondary trailer mountingassembly 6 is shown as a fifth wheel assembly 28 that is mounted to atop of the frame 24. The fifth wheel assembly 28 may include an upwardlyfacing portion having a slot for receiving a corresponding protrusion(or locking pin or kingpin) from the secondary trailer 12 b forremovable mounting or coupling of the secondary trailer 12 b to theconverter dolly apparatus 14. The fifth wheel assembly 28 is supportedin some embodiments by a spring suspension system (not shown). In someembodiments, for example, the spring suspension system is for dampeningdisplacement of the second trailer 12 b along an axis perpendicular to,or substantially perpendicular to, the central longitudinal axis of theapparatus 14.

As set out above, the apparatus 14 includes a kinetic energy recoverydevice 30 or a charge generating system that generates an electriccharge during certain mechanical actions by the apparatus 14. Theelectric charge in some embodiments is used to charge an energy-storingdevice 32, such as a battery, that is mounted to the frame 24. In someembodiments, for example, the energy-storing device 32 is housed withinan enclosure or housing 34 to protect the energy-storing device 32 fromany damage. In some embodiments, for example, the enclosure 34 iswaterproof and durable.

A schematic diagram of the kinetic energy recovery device 30 or chargegenerating system is shown in FIG. 2 b.

As schematically shown in FIG. 2b , the kinetic energy recovery device30 includes a set of one or more electric motor-generators 36 (two inthe example embodiments of FIGS. 2a and 3), mounted to an electric axle37 that connects the wheels 22 (as shown in FIG. 2a ). Themotor-generators 36 are used to convert the electric energy stored inthe energy-storing device 32 to mechanical energy by applying a motiverotational force to the wheels 22 thereby rotating the wheels 22 (drivemode), or to convert mechanical energy from the rotating wheels 22 intoelectric power (generator mode) by applying a regenerative braking forceto the wheels 22 thereby braking or effecting deceleration of the wheels22. In the example embodiments of FIGS. 2a, 2b , and 3, the electricmotor-generators 36 are located proximate the wheels 22 of the apparatus14. In some embodiments, for example, each wheel 22 includes a hubwherein the electric motor generators 36 are mounted within therespective hub of the wheels 22. Although two motor-generators 36 areshown, it will be understood that the kinetic energy recovery device 30may include only a single motor-generator (such as located along theaxle between the two wheels 22 through a differential 116) or mayinclude more than two motor-generators 36. The motor-generator 36controls the movement of the wheels 22 via the axle 37 based on signalstransmitted from a dolly controller 502. The controller 502 will bedescribed in more detail below.

The energy-storing device 32 stores energy generated by the kineticenergy recovery device 30. In some embodiments, a motor-generator drive38 receives the electric power generated through regenerative braking ofthe apparatus 14 to charge the energy-storing device 32; themotor-generator drive 38 can later use this stored power to power theelectric motors 36. In some embodiments, kinetic energy may be convertedinto electric form by regenerative braking when the truck's engine isrunning at high efficiency and the battery is at low charge.

The active converter dolly apparatus 14 may further include a pluralityof onboard instrumentation within a control system or controller 502that communicate with equipment, such as sensors 40, that may be usedfor, among other applications, assistance with steering and stability.In some embodiments, the sensors 40 may be used to assist in aligningthe first and second trailers 12 a and 12 b when the tractor-trailer 10is moving in reverse. In some embodiments, the sensors 40 may be used todetect low-traction conditions and stabilize the vehicle in motion.These applications are set out in further detail below.

Furthermore, in some embodiments, sensors may be used to help identifythe relative position of the converter apparatus 14 to other elements orcomponents of the tractor-trailer 10. The output from the sensors 40 canbe fed into one or more dolly control systems (located within theenclosure 34 in some embodiments), when such information can be used tocontrol the apparatus 14. (A schematic diagram of a dolly control systemis shown and described in more detail below with respect to FIG. 5.)

FIG. 3 is a schematic rear view of the dolly of FIG. 2a . Somecomponents of the dolly have been removed for ease of understanding ofthe disclosure. For instance, one set of wheels 22 and parts of theframe 24 have been removed.

In some embodiments, for example, the kinetic energy recovery device 30includes an electric motor-generator wheel assembly 50 that can be seenas an integrated electric motor wheel assembly. Although not shown, asimilar wheel assembly is preferably mounted adjacent the other wheel22. These two electric motor-generator wheel assemblies 50 may invarious embodiments include two motor-generators 36 driving two axles(one for the wheels 22 on each side of the frame 24), one or moremotor-generators 36 driving a differential 116 attached to two driveshafts 110,111, or one or more motor-generators 36 driving a singlecommon axle attached to the wheels 22 on both sides of the frame 24.

In operation, as the tractor-trailer 10 starts to brake, themotor-generator wheel assembly 50 captures the kinetic energy of theapparatus 14, with this energy flowing via the motor-generator drive 38to the energy-storing device 32. The combination of electricmotor-generators 36 and drive 38 converts the kinetic energy intoelectricity before it is transmitted to the energy-storing device 32.

In some embodiments, braking of the tractor-trailer vehicle 10 isdetected through the brake lines and/or the electrical connection 72from the towing vehicle 13 to the dolly apparatus 14. In otherembodiments, this method of braking detection may be replaced orsupplemented with one or more sensors incorporated into the apparatus 14to detect acceleration and deceleration and to operate the drive modeand generator mode of the motor-generators 36 accordingly. For example,some embodiments may eliminate the need for real time braking data fromthe towing vehicle 13 by incorporating one or more force sensors intothe dolly 14. The force sensors may be strain gauges and/or load cellsto sense the pull/push forces. The force sensors may be locatedsomewhere on the frame 24, on the second trailer connector assembly 6,or on the first trailer connector assembly 7. In the example embodimentshown in FIG. 14, force sensors 80 such as strain gauges areincorporated into the pintle hook or hitch 26 forming the first trailerconnector assembly 7. These force sensors 80 are configured to detectcompression and tension in the hitch 26, corresponding generally tobraking (deceleration) and acceleration of the tractor-trailer 10. Whenthe converter dolly 14 is being “pulled” (e.g. when the hitch is undertension), the motor-generator 36 will apply tractive motive rotationalforce or motive rotational force to reduce the pull force (drive mode),hence assisting the towing vehicle 13 engine to pull the trailer load.On the other hand, when the converter dolly is being “pushed” (e.g. whenthe hitch 26 is under compression), the motor-generator 36 will be inthe regenerative braking mode (generator mode) to reduce the “pushforce”, thus harvesting the kinetic energy of the trailer duringbraking. A close-loop PID controller can be used in some embodiments tominimize the “pull” or “push” force at the force sensors 80 byfine-tuning the PID coefficients. Additionally, some embodiments may usetwo additional force sensors 80 on left and right sides of the converterdolly's pintle hook or hitch 26 to measure the force vector acting onthe electric converter dolly 14. The force vector will provide left orright direction vector information in addition to knowing whether theconverter dolly is being “pulled” or “pushed”. The pintle hook or hitch26 with the load cell sensors 80 may in some embodiments be designed asa replaceable component, to allow ease of replacement in the case ofbroken sensors. In some embodiments, such a control system will notrequire any information from the towing vehicle 13, thus allowing theelectric converter dolly 14 to be a complete standalone unit.

A battery and control enclosure 34 is mounted on the frame 24. Invarious embodiments it may be mounted to the frame 24 on the sides, therear second end 9 as shown in FIG. 2a , or close to the front first end8 as described below with respect to the embodiment of FIG. 14. Thecontrol enclosure 34 may be formed from a durable waterproof andcorrosion resistant material such as a composite or aluminum, which maybe lightweight for fuel economy reasons. By being both waterproof andcorrosion resistant, the enclosure 34 in some embodiments provides adurable compartment for the converter apparatus 14.

Turning to FIG. 4, a perspective view of one embodiment of a batteryenclosure 34 is shown. As illustrated, the walls of the enclosure 34 areshown as being transparent so that the contents of the enclosure can beseen.

In this embodiment, the enclosure 34 houses a control module 60 and anenergy-storing device 32 (shown here as a battery). The control module60 may in various embodiments performs multiple functions for theapparatus 14. In some embodiments, the control module 60 is used tomonitor and control the energy-storing device 32. It can also be used tocontrol the motor-generators 36 through their drives 38 in both drivemode and generating mode. Furthermore, the control module 60 may monitorand control the charging of the energy-storing device 32, such as viaexternal plug-in sources. The control module 60 may also include anintelligent power dispatch system to determine when to power the wheelsvia the motor-generators 36. Furthermore, the control module 60 mayinclude an intelligent steering system to control braking and tractionof opposite wheels, or to provide shunting operation of the activeconverter dolly, or both. In some embodiments, the control module 60 maybe used to set up the kinetic energy recovery device 30 for regenerativebraking or for providing auxiliary power depending upon the roadcircumstances and the condition of the load on the tractor engine. Theoperation of the controller in various embodiments is described ingreater detail below.

In some embodiments, for example, the enclosure 34 also houses theenergy-storing device 32, which in the preferred embodiment is a modularlithium-ion battery system. The enclosure 34 may also house a sensorinterface 62 which communicates with the sensors 40 located throughoutthe dolly. The sensor interface 62 may communicate with the sensors 40,to assist, for example, with using the apparatus 14 to direct thesteering of the trailer(s) when the tractor trailer is moving inreverse. While shown separately, the sensor interface 62 can beintegrated within the control module 60.

In some embodiments, the enclosure 34 may also house a gyroscope sensor64 attached to the frame 24 and an off-board power interface 66. Thegyroscope sensor 64 may be in communication with the dolly controlsystem to transmit signals which can be used, for example, as part of aself-balancing control system for the converter dolly apparatus 14. Insome embodiments, for example, the controller 502 may receive andprocess the signals from the gyroscope sensor 64 and use self-balancingdata from the signals (e.g. data on the angular pitch acceleration ofthe apparatus 14 about a left-to-right central axis of the apparatus 14)to drive the motor-generators 36 to control rotation of the wheels 122to maintain the level orientation of the apparatus 14 in aself-balancing mode. In the event that the apparatus 14 isself-balancing, the presence of a support leg or support apparatus 27may not be necessary.

The off-board power interface 66 may be used to connect theenergy-storing device 32 to off-board charging systems or off-boardloads. The enclosure 34 may include a communication interface 68 thatcommunicates with towing vehicle engine information system. In someembodiments, the communication interface 68 is part of the controlmodule 60. It may in various embodiments be a wired electrical or awireless communication interface, such as a radio interface (using awireless protocol such as e.g. 802.11), and it may communicate with thetowing vehicle 13 via the tractor's on-board diagnostics (OBD-II) port.The communication interface 68 may in some embodiments be able to accesscontroller area network (CAN) bus data from the towing vehicle 13. Insome embodiments, the communication interface 68 may be able to senddata from the apparatus 14 to the towing vehicle 13, such as controlsignals used to control vehicle systems in the towing vehicle 13.

The communication interface 68 may be configured to receive varioustypes of data from the towing vehicle 13, and in some embodiments fromthe first trailer 12 a as well. This data may include the throttle levelof the main tractor; the engine motive rotational force; the enginespeed; the parking brake state; the transmission state; the brakeactivation state; or any other information accessible in the towingvehicle 13. This data may in various embodiments be used by the activeconverter dolly control system to determine when to recover, and when toexpend, recovered energy to assist in increasing the fuel economy of thetractor-trailer system.

In some embodiments, a forward exterior surface of the battery enclosure34 may be configured to reduce drag. Various aerodynamic profiles can beused, and the profile shown in FIG. 3 is not intended to be limiting. Insome cases, the low positioning of the battery enclosure may allow for aground effect design to be employed, meaning that the shape will takeinto account both the passage of air from in front and past the leadingedge, as well as air passing below the leading edge between the leadingedge and the ground. In some embodiments, for example, the enclosure 34may also house a cooling system for cooling the energy-storing device 32and the other electronic components housed within the enclosure 34. Insome embodiments, for example, the cooling system is liquid cooled,while in others it is air cooled. In some embodiments, the enclosure 34is located at a low level between the wheels 22 such that the weight ofthe battery and control systems within the enclosure 34 are located aslow down as is practical to have a lower centre of gravity to improveroad handling and control of the apparatus 14 during transport.Accordingly, in some embodiments, the housing or enclosure 34 isdisposed on or mounted to the frame such that the apparatus has a centreof gravity disposed below a central, midline axis of the apparatus. Inanother embodiment, the system may include a lightweight compositechassis or frame 24 which is aerodynamic by design and includes one ormore enclosures 34 for the batteries and controls.

Turning to FIG. 5a , a schematic diagram of a control system 500 for theapparatus 14 is shown. In the illustrated embodiment, certain componentsof a second trailer 12 b which are in communication with the apparatuscontrol system 500 are also schematically shown.

The apparatus control system 500 includes an intelligent controller 502which is, in some embodiments, implemented within a central processingunit (CPU). In the illustrated embodiment, the controller 502 is incommunication with the tractor OBD (on-board diagnostics) unit, such asan OBD-II port, via a power line communicator unit 504 to receive thetractor or truck (e.g. tractor, truck, car or cab) and tractor engineinformation. Wireless communication, such as a radio-based communicationinterface, can also be used instead of or in addition to the power linecommunicator unit 504 to connect the tractor OBD to the dolly controlsystem 502. The dolly control system 502 may also communicateinformation to the towing vehicle 13 via the communication interface 68in some embodiments.

The dolly control system 502 also communicates with the set of sensors40, such as but not limited to, a global navigation satellite system(GNSS) tracking devices, such as global positioning system (GPS)transceiver, an Inertial Measurement Unit (IMU) sensor, one or morewheel speed sensors 70, 71 each placed on one of the wheels 22 or axlesof the apparatus 14, one or more linear accelerometers 74, and/or thegyroscope sensor 64. The wheel speed sensors 70, 71 measure individualwheel speeds of the dolly apparatus 74 to capture magnitude anddirection (e.g., forwards or backwards) of the dolly apparatus 74, asdescribed elsewhere herein. The gyroscope sensor 74 and the linearaccelerometer 74 may be mounted onto the frame 24 around the center ofthe dolly apparatus 74. The gyroscope sensor 64 may be used to monitorangular acceleration of the dolly apparatus 74 and the linearaccelerometer 74 will be used to sense the linear acceleration of thedolly apparatus 74 as described elsewhere herein, as described elsewhereherein.

The intelligent controller 502 may be use the sensor data to trigger acorrective response. The wheel speed sensors 70, 71 monitor individualwheel speeds and may trigger the corrective response when the differenceof the wheel speed is larger than a preset threshold, as describedelsewhere herein. This may occur when one wheel is slipping and spinningmuch faster than the other wheel on the same axle. This scenarioindicates the vehicle is losing traction and in most cases losingcontrol. □The accelerometer 74 combined with the gyroscope sensor 64monitor the linear and angular acceleration of the dolly apparatus 74.When the vehicle is moving forward (i.e., longitudinal direction), asudden increase in the angular acceleration around the vertical z-axis(i.e., yaw motion) may trigger a corrective response.

The intelligent controller 502, in the case of one motor drive system,connects to a differential and transfers power to the two wheels. Whenslipping of the wheels or a sudden increase of yaw acceleration aredetected, an electronic locking device wheel will lock the differentialdrive, effectively turning it into a solid axle. This action willtransfer the motive rotational force to the wheel with traction, therebyreducing the instability of the dolly apparatus 74. Additionally, whenslipping of the wheels occurs, the intelligent controller 502 will cutpower to the motor to reduce the motive rotational force output to thewheels.

In the case of independent wheel motors drive system, individual wheelspeed and motive rotational force will be controlled by the intelligentcontroller 502. When a wheel slipping occurs, the intelligent controller502 will control the speed of the wheels via motive rotational forcecommand to match the corresponding vehicle speed. When a sudden yawacceleration occurs, the intelligent controller 502 will adjust themotive rotational force applied to the wheel in the opposite directionto counter the detected yaw acceleration, thereby reducing the overallyaw acceleration of the dolly apparatus 74.

When the speed difference of both wheels on the same axle and/or the yawacceleration of the dolly apparatus 14 is reduced to the presetthreshold, the intelligent controller 502 will stop applying thecorrective motor response.

The intelligent controller 502 is also in two-way communication with abattery and battery management system (BMS) unit 506 and amotor-generator drive 508 in some embodiments. The battery and BMS unit506 is also connected to the drive 508. The motor-generator drive 508 isfurther connected to, or in communication with, the set ofmotor-generators 36 (see FIG. 2b ) that are associated with anindividual wheel 22. As schematically shown in FIG. 2b , the number ofmotor-generators 36 in the illustrated set is two.

The intelligent controller 502 is also connected to a database 510including road grade information 512 which can be stored within adatabase or based on sensor information, or real time road informationby connecting the dolly intelligent controller 502 to wireless network.

Separate connectors, seen as an electric connector from the trailer 518and an electric connector to the trailer 520 are also connected to theelectric line 516. As will be understood, one of the connectors 518 or520 is connected to the first trailer and the other connector isconnected to the second trailer.

The intelligent controller 502 may in some embodiments further includean interface of a module allowing the controller to be monitored by auser over the Internet, such as via the communication interface 68.

The truck or tractor includes a power line communication unit 522 thatconverts information from a vehicle on-bard diagnostics (OBD) system 524to be sent via the truck electric lines. In another embodiment, the OBDinformation can be converted and transmitted wirelessly, such as via thecommunication interface 68. The truck or tractor power linecommunication unit 522 is connected to the electric line 526 which, inturn, is connected to an electric connector to a trailer 528, In use,the electric connector to trailer 528 and the electric connector fromtrailer 518 are connected via a cable to each other to deliver power andOBD information from the truck to all the connected trailers and dolliesto the tractor.

Collectively, the electric connector from the trailer 518, electricconnector to the trailer 520, electric line 516, electric line 526, andelectric connector to a trailer 528 shown in FIG. 5 all form part of theelectrical connection 72 configured in various embodiments to carryinformation, or electrical power, or both between the varioustractor-trailer vehicle 10 components (i.e. the towing vehicle 13, thefirst trailer 12 a, the dolly apparatus 14, and the second trailer 12b).

In some embodiments, the transmission of signals between the vehicle OBD524 and the intelligent controller 502 is via the electric line when thesignals from the vehicle OBD are converted by the power linecommunicator unit 522 which then uploads the converted signal to thetruck electric line. At the dolly end, the signals are received by thepower line communication unit 504 which then extracts the converted OBDsignals and then decrypts or converts these signals into a formatunderstood by the controller 502. In another embodiment, the signals maybe communicated or transmitted wirelessly between the vehicle OBD andthe intelligent controller using the communication interface 68.

In operation, as the tractor-trailer is in motion, the intelligentcontroller 502 receives and transmits signals to the other components ofthe controller system. For instance, the intelligent controller 502 cancommunicate with the sensors 40 to receive signals representing variousdata that the controller 502 can use to assist in improving operation ofthe tractor-trailer and the dolly.

A method of convertor dolly control is shown with respect to FIG. 5b .As the truck is driving, the vehicle OBD 524 collects various truckinformation with respect to characteristics of the truck. For instance,this information may include, but is not limited to, a position of thebrake pedal or braking motive rotational force, amount of motiverotational force being generated by the engine, the speed of the engine,etc. The sensors may also collect sensor information associated withvarious dolly characteristics such as listed above. Other informationmay include road grade information, map information or any real-timeinformation and the like.

All, or parts of this, information is then transmitted to, and receivedby, the intelligent controller 502 within the dolly (step 1000). Interms of the signals received from the vehicle OBD, in some embodiments,the digital signals from the vehicle OBD 524 are converted by the powerline communication unit 522 and then transmitted over the truck electricline 526. These signals are then retrieved, or received, by the powerline communicator unit 504 within the dolly and then extracted, and, ifnecessary, re-converted before being received by the controller 502. Aswill be understood, the power line communicator unit 504 converts theextracted signals into a format understandable by the controller 504. Aswill be understood, due to the connection between the dolly and thetrailers (via the connectors 518 and 520), the dolly control system 502has access to any signals and electricity that is transmitted over theelectric line 526.

In some embodiments, the digital signals may be transmitted wirelesslyfrom the vehicle OBD 524 to the controller 502 via the communicationinterface 68.

After the controller 502 receives the digital signals, the controllerprocesses the signals (step 1002) and then generates dolly controlsignals to control the dolly (step 1004) based on the digital signals.The dolly control signals may also be seen as motor-generator drivecontrol signals.

For instance, if the towing vehicle 13 is braking, the controller 501may receive digital signals representing the level of braking beingapplied to the truck. In one embodiment this is determined by thevehicle OBD by monitoring the position of the brake pedal within thetruck. After receiving the digital signals, either directly from thevehicle OBD or converted by the power line communicator unit, thecontroller can generate and send a signal to the motor-generators 36(via the motor-generator drive 508) to apply a correspondingregenerative brake motive rotational force. In this manner, during thisregenerative braking, the battery can be charged based on the brakingmotive rotational force value calculated by the controller.

In another embodiment, the controller 502 may receive a digital signalindicating that the truck is being started. If the battery is charged orhas some charge, the controller may generate and transmit a signal tothe motor-generator to apply or generate a motive rotational force toassist startup of the truck to improve the efficiency of the truckmotor.

In another embodiment, if the state of charge (SOC) within the dolly'sbattery is low, signals relating to the truck engine's maximumefficiency may be received by the controller whereby the controller maythen generate and transmit a signal to the kinetic energy recoverydevice to charge the battery when possible.

Turning to FIG. 5c , a flowchart outlining a method of communicationfrom the dolly control system is shown. Initially, dolly informationsignals, which are typically digital, may be converted (step 1010) ifthey are being transmitted to a truck driver over the electric line asdiscussed above. The dolly information may include information relatingto the dolly's position, the battery charge, or the like.

The dolly information signals are then transmitted (step 1012) tospecified destinations or individuals, such as, but not limited to, thetruck driver or a fleet manager. As will be understood, the signals maybe transmitted wirelessly via the communication interface 68 or via theelectric line 526 to the truck driver. The step of signals beingtransmitted to the fleet manager is generally performed wirelessly.

The active converter apparatus 14, as outlined above, may be consideredin some embodiments a TTR hybrid system. As such, the dolly apparatus 14in some embodiments operates in different operational modes.

In one mode, the active converter dolly 14 does not participate inextracting or providing power to the tractor-trailer system. In thismode the converter dolly will be passive. In another mode, sometimesreferred to as an anti-idling mode, auxiliary loads (for example cabin'sor trailer's A/C system) are driven by the kinetic energy recoverydevice 30 of the dolly 14 or the stored energy in its energy storingdevice 32. In yet another set of modes, such as a drive mode and astability-assistance mode, the energy in the dolly's energy storingdevice 32 is used to provide traction motive rotational force in thedolly's tires 22 to assist the motion of the tractor-trailer vehicle 10.In another mode, referred to as generator mode, the dolly is used toextract and convert the mechanical power in the rotation of its wheelsinto electric power via its motor-generators using regenerative braking.The electric power then can be stored in the energy storing device 32and/or run auxiliary devices of the tractor-trailer vehicle 10. Thismode may activated during regenerative braking or when the truck-trailerdrives downhill, or when the energy storing device 32 needs to becharged, in which it may be activated when the engine is operating athigh efficiency.

In a further mode, called electric-vehicle (EV) mode, the dollyapparatus 14 may use the power stored in the energy storing device 32 topower the motor-generators 36 to push the entire tractor-trailer vehicle10 forward when it is moving at low speeds. In another mode, calledbackup-assistance mode, the motor-generators are employed to stabilizeand straighten the tractor-trailer vehicle 10 when backing up.

Some of these modes are described in more detail below.

In further designing one embodiment of the dolly, certain drivingconditions are considered. These conditions may include, but are notlimited to, acceleration (when the vehicle's velocity is increasing);deceleration (when the driver releases the accelerator pedal and maypress the brake pedal); and cruising (when the road load and thevehicle's velocity are constant).

An example of drive mode is as follows. During acceleration, if there isenough charge in batteries, and when the state of charge (SOC) of thebattery is greater than the SOC threshold acceleration, the dolly mayassist the truck's powertrain via the electric motor associated with thedolly wheels, providing an additional boost motive rotational force inaddition to the motive rotational force generated by the tractor. In oneembodiment, the SOC threshold acceleration can be a predeterminedthreshold calculated via experiments or system optimizationcalculations. This boost motive rotational force depends on vehiclespeed, the battery's SOC, and the accelerator pedal position. A samplemap for electric motor output during acceleration at a sample vehiclespeed equal to 50 km/h for various battery SOCs is shown in FIG. 7.

An example of generator mode is as follows. During deceleration, if thebattery is or batteries are not fully charged, the dolly 14 typicallydoes not assist the truck or other towing vehicle 13 nor add any load tothe truck to extract any energy. During coasting and based on thebattery's SOC, the dolly 14 may extract power via the motor-generator 36for charging the batteries 32. However, when the brake pedal isdepressed, parallel regenerative braking is actuated. Depending onvehicle speed and consequently, the generator's rotational speed, forapproximately 10-20% of initial brake pedal travel, the friction brakesare not engaged and only regenerative braking is applied. During harderbraking conditions, depending on the value of generator speed and maxmotive rotational force, the braking energy may not completelyregenerated. In these situations, the excessive amount of braking motiverotational force is applied by friction braking, as shown in FIG. 8.This process is called brake motive rotational force blending.

An example of alternating drive mode and generator mode is as follows.During cruising, depending on the status of load, or drive motiverotational force, relative to optimum load, or drive motive rotationalforce, the dolly 14 may assist the truck powertrain, being in drivemode, or extracting power via the generator in generator mode. In thissituation, if the truck powertrain motive rotational force is greaterthan the optimum motive rotational force of the engine at that speed,the dolly will be in assist mode (i.e. drive mode), in which theelectric motor of the motor-generator 36 provides a boost motiverotational force in addition to the truck motive rotational forceoutput, as shown in FIG. 9a . Consequently, there is a lower motiverotational force request from the engine due to the available motormotive rotational force, which results in a more-efficient tractoroperating point. Finally, if the engine toque is less than the optimumload, or drive motive rotational force, the dolly 14, depending on theSOC of the battery 32, will be in generator mode: the truck powertraindelivers its power to the load and the load delivers power to electricpowertrain, as shown in FIG. 9b . In this situation, some portion ofengine power is stored in the batteries 32 by the motor-generator 36,and the extra requested motive rotational force from the drive of thetowing vehicle (such as an internal combustion engine, ICE) moves thecurrent towing vehicle drive operating point to a more efficient one.

With respect to some embodiments of the active converter dolly, certaincharacteristics of the dolly are required. More specifically, power andperformance, powertrain configuration, and steerability are taken intoaccount in the design of some embodiments of the active converter dolly14.

With respect to the powertrain configuration, two scenarios, seen as anin-wheel motor embodiment and a drive axle embodiment can be considered.

For embodiments with an in-wheel motor configuration, the kinetic energyrecovery device 30 includes two drive shafts 110,111 with two in-wheelmotor-generators 36, such as schematically shown in FIG. 10. As shown inFIG. 10, the apparatus 14 is connected to the second trailer 12 b. Themotor-generators 36 can provide the required power for driving, and byapplying different traction forces, it can play the role of a steeringsystem. While this configuration may require a higher level ofmodification to be retro-fitted into existing converter dollies, it maymore suitable for Vehicle Dynamic Control (VDC) applications because theleft and right motors can be operated independently to provide differenttraction/braking motive rotational force to each wheel. By controllingthis properly, a corrective yaw moment is formed, which can be used toimprove dynamical behaviour of the combination of the towing vehicle,trailers, and the converter dolly.

For the drive-axle embodiment, in this configuration, the axle 37 is adrive axle such as schematically shown in FIG. 11. Unlike the system ofFIG. 10, the level of modification for this configuration is lower.Furthermore, in some embodiments, the motor-generator includes amotor-generator reduction gear which can also be embedded into the axle37 (double reduction axle).

When the active converter dolly or apparatus 14 is disconnected from afirst trailer 12 a but still connected to a second trailer 12 b, theapparatus 14 can be used to move the second trailer 12 b without havingto go through the hassle of re-mounting the first trailer 12 a. Withrespect to steerability, in the in-wheel motor configuration shown inFIG. 10, the steering may be altered by differential motive rotationalforce applied by each motor-generator 36. In the drive-axleconfiguration shown in FIG. 11, a steering mechanism 1200 may beintegrated with the converter dolly 14. A schematic of the steeringmechanism 1200 that can be used for an active converter dolly 14 isshown in FIG. 12. The steering can be achieved by using a motor 1202.Either an electric or a hydraulic linear actuator 1204 can also providethe retractability of the steering mechanism, which can also be seen asa third wheel assembly or coaster wheel 1206. However, since using ahydraulic actuator may require additional power sources and accessories(hydraulic power and connections), some embodiments may use an electriclinear actuator. In some embodiments, for example, a steering device forreleasably coupling to the steering mechanism is provided for assistingwith steering of the apparatus 14 and second trailer 12 b when theapparatus 14 and second trailer 12 b are disconnected from the firsttrailer 12 a. In some embodiments, for example, the steering deviceincludes a steering column and steering wheel.

Using the related equation of motion for the articulated vehicles, thesteerability of both configurations (of FIGS. 10 and 11) wereinvestigated. FIGS. 13a and 13b illustrate the turning radius of thetrailer equipped with an active converter dolly with differential motiverotational force steering (FIG. 13a ) and steering mechanism (FIG. 13b )configurations.

It can now be appreciated that the active converter dolly or apparatus14 may not only improve fuel economy when it is attached to thetractor-trailer but can also be used to shunt a trailer when it is notattached to a trailer with adding a steering mechanism. Although notshown, a steering wheel, joystick, or other interfaces can also beincluded to communicate with the dolly controller to enable a driverlocally or remotely to steer the dolly. As such, the dolly can be usedto shunt the second trailer around a staging area even when the secondtrailer is disconnected from the tractor. This may be to place thesecond trailer in position for loading or unloading, or to place it inposition for being attached to a trailer. Because the apparatus 14 isequipped with a steering system and by the dolly control system, theapparatus 14 can be directed or steered into position. In someembodiments, the steering can be manually applied, such as by way of aremote control device. Such a device may be a joystick, smart phone ortablet device which includes software access to the steering control ormechanism. In this way the apparatus 14 can be controlled remotely whileit is being maneuvered into position. Collision avoidance sensors mayalso be used to help avoid accidents. The collision avoidance sensorsmay be ultrasonic sensors, LIDAR, RADAR, or other suitable proximitydetector sensor. The collision avoidance sensors may be mounted on thesecond trailer 12 b or may be mounted on the apparatus 14 in a way thatpermits the dolly sensors to see past the edges of the second trailer 12b for collision avoidance.

In some examples, a steering device may be coupled to the steeringmechanism. The steering device may be communicatively coupled to thecontroller for locally or remotely steering the apparatus 14 by anoperator (e.g. driver), the apparatus 14 being operable by the steeringdevice to shunt the second trailer 12 b around a staging area when thesecond trailer 12 b is disconnected from the towing vehicle 13. Thesteering device may comprise a steering wheel or joystick mounted to theapparatus 14. The steering device may be a wireless communication devicefor wireless communicating with the controller, such as a wirelessremote control having a steering wheel or joystick, smartphone ortablet, the wireless communication device having control software forproviding a user interface for steering the apparatus via userinteraction therewith.

The collision avoidance sensors may be communicatively coupled to thecontroller. The collision avoidance sensors may be mounted to theapparatus or the second trailer to detect any objects within a thresholddistance of the apparatus or the second trailer, and the controllerconfigured to generate an alert when an object is detected within thethreshold distance of the apparatus or the second trailer.Alternatively, the controller may be configured to send a notificationof the steering device when an object is detected within the thresholddistance of the apparatus or the second trailer, with the steeringdevice configured to generate an alert when an object is detected withinthe threshold distance of the apparatus or the second trailer. The alertmay be one or more of an audible alert, visual alert, or physical alertsuch as a vibration.

Turning to FIG. 6, another schematic embodiment of an active converterdolly 14 in a B train configuration 600 is shown, in which the activeconverter 14 is part of the first trailer 12 a. In this configuration,the fifth wheel assembly 28 sits on the rear axle of the first trailer12 a. Similar to the embodiment discussed previously and shown in FIG.1, which may be referred to as an A train configuration, the activeconverter dolly 14 in a B train configuration 600 is capable of addingpower to drive the trailers and to being able to capture energy fromregenerative braking. In B train active dollies, at least one of theaxles may be electrified as discussed above for adding power to drivethe trailers and to being able to capture energy from regenerativebraking. Similarly, in A train active dollies with multiple axles, atleast one of the axles may be electrified. Electrifying more axles mayimprove the fuel efficiency and performance of the active converterdolly apparatus 14.

Turning to FIG. 14, a perspective view of a second example embodiment ofan active convertor dolly is shown.

In this embodiment, the active converter dolly apparatus 614 includesthe same overall structure as the apparatus 14 of FIG. 2a : a frame 24including a wheel supporting portion 9 and tongue portion 8; a firsttrailer connection assembly 7, illustrated here as a hitch 26; two setsof wheels 22 mounted to the wheel supporting portion 9; and a secondtrailer mounting assembly 6 in the form of a fifth wheel assembly 28mounted to the top of the frame 24.

However, several of the components are have been relocated or altered inthis embodiment relative to the embodiment of FIG. 2a . Theenergy-storing device 32 of FIG. 2a is replaced here with a batteryarray 632, and the enclosure 34 is not shown in this illustration. Thesupport leg or apparatus 27 of FIG. 2a is shown here in the form of adetachable trailer jack 627. The trailer jack 627 can be used to raiseor lower the height of the tongue portion 8 of the apparatus 14 usingthe included hand-operated crank 650. This embodiment of the apparatus14 also includes a trailer jack drive 652 coupled to the kinetic energyrecovery device 30. The trailer jack drive 652 is powered by the batteryarray 632, operable to raise or lower the trailer jack 627 as analternative to the crank 650.

The various components of the kinetic energy recovery device 30 are alsorelocated in this embodiment from the wheel supporting portion 9 to thetongue portion 8. By locating the battery array 632 and kinetic energyrecovery device 30 to the tongue portion, or to an area intermediate thefirst trailer connector assembly 8 and the second trailer connectorassembly 6, this embodiment locates these components farther from theunderbody of the second trailer, thereby potentially facilitatingcooling and reducing mechanical interference from the second trailer 12b. By locating the battery array 632 and sensitive components of thekinetic energy recovery device 30 to a location intermediate the firsttrailer connector assembly 8 and the second trailer connector assembly6, the likelihood of mechanical interference from the first trailer 12 ais also reduced. In some embodiments, for example, the tongue portion 8defines an opening wherein the battery array 632 and other components ofthe kinetic energy recovery device 30 are disposed within the openingand secured to the frame 24.

FIG. 15 is a rear view of an example dolly apparatus 14 with an in-wheelmotor configuration, showing details of the axle and wheelconfiguration. The apparatus 14 has a first wheel 102 on a first side ofthe frame 24, driven by a first motor-generator 106 and connected to afirst drive shaft 110. A first wheel speed sensor 70 is located at thefirst wheel assembly. The first wheel speed sensor 70 may be attached tothe first wheel 102 or the first drive shaft 110 for collecting wheelspeed data and providing it to the controller 502. The apparatus 14 alsohas a second wheel 104 on a second side of the frame 24, driven by asecond motor-generator 108 and connected to a second drive shaft 111. Asecond wheel speed sensor 71 is located at the second wheel assembly.The second wheel speed sensor 71 may be attached to the second wheel 104or the second drive shaft 111 for collecting wheel speed data andproviding it to the controller 502.

FIG. 16 is a rear view of an example active converter dolly apparatus 14with a two axle-differential configuration, showing details of the axleand wheel configuration. The converter dolly 14 includes a two-partcentral axle split into a first drive shaft 110 and a second drive shaft111, one electric motor-generator 36, and a differential 116. The firstdrive shaft 110 and second drive shaft 111 may in some embodiments bereleasably locked together by an axle locking device 114 in response toa wheel-locking control signal from the controller 502. When lockedtogether, the first drive shaft 110 and second drive shaft 111 rotate asa single axle.

In the differential configuration of FIG. 16 there may be less space tohouse the enclosure 34 between the wheel sets, however, the otheraspects remain the same. The enclosure 34 may require an adaptation topermit the drive shafts 110,111 to traverse the compartment, and themotor-generator 36 also needs to be connected through the differential116. However, even with a central transverse axle, this embodiment mayinclude the aerodynamically efficient, lightweight, waterproof andcorrosion resistant battery enclosure 34 and an instrumentation packageof appropriate modules to allow for interfacing with the towing vehiclemotor control system, to interface with the proximity sensors to providea back-up steering system, to interface with a remote controller topermit the dolly to be remotely steered around even when disconnectedfor the tractor trailer train and will allow the dolly to operateequally well in forward or reverse.

FIGS. 17 to 20 show the operation of the controller 502 in relation toother vehicle systems while operating in the various modes describedbriefly above.

In FIG. 17, an example operation of the stability-assistance mode isshown as a flowchart. At step 1702, the controller 502 operates todetect a low-traction condition based at least in part on data providedby the first wheel speed sensor 70, the second wheel speed sensor 71,the gyroscope sensor 64, and the linear accelerometer 74. In someembodiments, this detection 1702 may be based entirely on data from thewheel speed sensors 70, 71 indicating that one wheel is rotatingsignificantly faster than the other, for example that the differencebetween the speed of the first wheel 102 and the speed of the secondwheel 104 is above a certain threshold. In other embodiments, this wheelspeed data may be supplemented or replaced in the detection step 1702 byangular acceleration data from the gyroscope sensor 64 and linearacceleration data from the linear accelerometer 74 indicating that theyaw acceleration (i.e. angular acceleration about a vertical Z-axis) ofthe dolly 14 has increased or is above a certain threshold while thedolly 14 is moving forward.

When the low-traction condition has been detected at step 1702, thecontroller then adjusts the motive rotational force applied to thewheels at step 1704. Depending on the configuration of the dolly 14, theadjustment may be to the motive rotational force applied to one or bothwheels of the apparatus 14.

For example, in a differential configuration such as the one shown inFIG. 16, the electronic locking device 114 will lock the differentialdrive, essentially turning the two drive shafts 110,111 into a singlesolid axle. Such action will transfer the motive rotational force to thewheel with traction and therefore reduce the instability of theconverter dolly 14. In some embodiments, when the low-traction conditionis detected, the system will also cut power to the motor-generator 36 toreduce the motive rotational force output to the wheels 102,104. Thismay be seen as the application of Vehicle Control System or VehicleStability System technology to the active converter dolly 14.

In an in-wheel motor-generator configuration such as the one shown inFIG. 15, the motive rotational force or motive rotational force appliedto the first wheel 102 by the first motor-generator 106 may be reducedif the first wheel 102 is detected to be slower than the second wheel104, and vice-versa with respect to the second motor-generator 108 andsecond wheel 104. Alternatively or in addition, the motive rotationalforce or motive rotational force applied to the slower wheel may beincreased, or regenerative braking may be applied (or increased inintensity) to the faster wheel.

When yaw acceleration is detected as part of the low-traction conditionat step 1702, the adjustment of motive rotational force or motiverotational force at step 1704 may comprise adjusting wheel motiverotational force to counteract the yaw acceleration. For example, whenclockwise yaw acceleration is detected, the motive rotational force ormotive rotational force applied to the first wheel 102 on the left sideof the frame 24 may be decreased, or the motive rotational force appliedto the second wheel 104 on the right side of the frame 24 may beincreased to generate offsetting counter-clockwise yaw acceleration.

At step 1706, the controller 502 detects that the low-traction mode isno longer present or has been addressed, and the corrective action isdiscontinued, returning the dolly 14 to a baseline operating mode inwhich the motive rotational force applied to each wheel follows thestandard rules set out above with regard to the various operating modes(drive mode, generator mode, passive mode). This determination may bebased on wheel speed data and/or angular and linear acceleration data.

In FIG. 18, an example operation of the electric-vehicle (EV) mode isshown as a flowchart. Electric-vehicle mode may be used by the dollyapparatus 14 to drive the tractor-trailer vehicle 10 forward inlow-speed conditions, such as slow-moving traffic congestion conditions,with or without the use of the drive of the towing vehicle (e.g.,internal combustion engine) being engaged. At step 1806, the controller502 operates to detect a set of conditions based at least in part onvehicle data 1801 received from the towing vehicle 13 and optionally theSOC of the energy storing device 32 (e.g., battery). The vehicle data1801 may be received in some embodiments over the electrical connection72 or the communication interface 68. As noted above, the dollyapparatus 14 may be connected to the OBD II port of the towing vehicle13 to monitor the real-time operating information from the CAN bus ofthe towing vehicle 13.

In the illustrated example, the vehicle data 1801 includes vehiclebraking data 1802 indicating the degree of braking being applied by thedriver of the towing vehicle 13, and vehicle speed data 1804 indicatingthe speed of the towing vehicle 13 or the entire tractor-trailer vehicle10. The braking data 1802 may indicate in some embodiments the degree ofdepression of the brake pedal of the towing vehicle, from 0% depression(no braking) to 100% depression (full braking).

In some embodiments, the conditions for activation of electric-vehiclemode include detecting at step 1804: that the degree of braking is belowa braking threshold, that the speed of the vehicle is below a speedthreshold, and that the charge of the energy storing device 32 is abovea SOC threshold. If these conditions are met, the electric-vehicle modeis activated at step 1808. The braking threshold, speed threshold andSOC threshold may vary between embodiments. For an example, the brakingthreshold may be between 10% and 50% braking, between 20% and 40%braking, between 25 and 35% braking or approximately 30%. For anotherexample, the speed threshold may be between 5 km/h and 45 km/h, between10 km/h and 40 km/h, between 20 km/h and 30 km/h, or approximatelybetween 25. For yet another example, the SOC threshold may be between10% and 40% of a full charge level, between 20% and 30% of a full chargelevel, or approximately 25% of a full charge level.

In electric-vehicle mode, the motor-generators 36 of the dolly 14 areused to drive the apparatus 14, and therefore the tractor-trailer 10,forward. For example, a first motor-generator 106 and secondmotor-generator 108 may be used to drive wheels on both sides of thedolly 14 forward to move the vehicle in slow speed conditions.

The controller 502 in some embodiments may deactivate electric-vehiclemode at step 1810 upon detecting that the conditions detected at step1806 no longer hold. For example, if the driver applies the brakes abovethe braking threshold, or if the charge level of the energy storingdevice 32 drops below the SOC threshold, or the speed of the vehiclerises above the speed threshold, then the electric-vehicle mode may bedeactivated.

In FIG. 19, an example operation of the anti-idling mode is shown as aflowchart. Anti-idling mode may be used by the apparatus 14 to powervarious electrical systems of the tractor-trailer 10 using the energystoring device 32 when the vehicle is idling, temporarily stopped orparked, without having to run the engine of the towing vehicle 13 tomaintain power. High voltage cables may be used to connect the apparatus14 to the first trailer 12 a and through the first trailer 12 to thetowing vehicle 13. A DC-DC converter may be used by the towing vehicleto step down the high voltage of the energy storage device 32 (i.e.,battery) to match the low voltage system of the auxiliary components ofthe towing vehicle 13. A control system may be used to automaticallyshut off the engine of the towing vehicle 13 and subsequently restartthe engine. Depending on the characteristics of the towing vehicle 13,the engine starter may be modified from manufacturer's condition so thatthe apparatus 14 may operate in the anti-idling mode.

The controller 502 operates to detect the conditions for activation ofanti-idling mode at step 1906, based at least in part on receivedvehicle data 1901. With respect to anti-idling mode in the illustratedexample, the vehicle data 1901 used by the controller 502 at step 1906includes vehicle transmission data 1902 indicating the state of thetransmission of the towing vehicle 13 (e.g. whether the engine is on butthe towing vehicle 13 is in park, neutral, reverse, or a drive gear). Insome embodiments, such as some embodiments configured to be used with atowing vehicle 13 with a manual transmission, the vehicle data 1901 mayalso include towing vehicle parking brake data 1904 indicating the stateof the towing vehicle's parking brake (e.g. engaged or not engaged).

Anti-idling mode may be activated by the controller 502 upon detectingat step 1906 that the towing vehicle 13 is stopped for at least apredetermined amount of time, the towing vehicle 13 is in a parkedstate, or both. The predetermined amount of time may vary between inembodiments. In some embodiments, the predetermined amount of time isbetween 10 and 60 seconds, between 15 and 45 seconds, or approximately30 seconds. Detecting that towing vehicle 13 is in a parked state is ina parked state may, in some embodiments, comprise detecting that thetowing vehicle 13 has its transmission set to a parked state based onthe transmission data 1902. In other embodiments, such as someembodiments configured to be used with a towing vehicle 13 with a manualtransmission, this may comprise detecting that the transmission is inpark gear and optionally detecting that the parking brake is engaged.

When anti-idling mode is activated at step 1908, the stored power in theenergy storing device 32 may be used to power one or more electricalsystems of the tractor-trailer 10 at step 1910. The power may be relayedvia the electrical connection 72. Examples of such systems include HVACsystems used in the towing vehicle 13; refrigeration or HVAC systemsused in the first trailer 12 a or second trailer 12 b; lights, stereosystem, or other user amenities in the towing vehicle 13; lights on thetowing vehicle 13 or the trailers 12 a,12 b; or any other electricalsystem on the towing vehicle 13, first trailer 12 a, second trailer 12b, or dolly apparatus 14. The voltage of the energy storing device 32may be significantly higher than the systems being powered in someembodiments; in such embodiments, the electrical connection 72 mayinclude one or more DC-DC converters or transformers as described abovefor stepping down the voltage.

In some embodiments, the controller 502 may further operate to shut offthe engine of the towing vehicle at step 1912 in response to activatinganti-idling mode. The controller 502 may send an engine deactivationsignal via the communication interface 68 or electrical connection 72,as further described above, to deactivate the engine of the towingvehicle 13 to prevent idling. In other embodiments, the engine may beshut down manually or some other system may be used to shut down theengine when anti-idling mode is active. Some embodiments may also beconfigured to restart the engine using a process as described above.

In FIG. 20, an example operation of the backup-assistance mode is shownas a flowchart. Backup-assistance mode in the illustrated exampleoperates in a similar manner to stability-assistance mode, but generallyoperates at lower speeds and is activated under different conditions.Its purpose is to keep the tractor-trailer straight when backing up andto prevent jack-knifing conditions whereby one or more of the trailers12 a, 12 b deviates from the longitudinal orientation of thetractor-trailer vehicle 10 as a whole.

At step 2002, much like in low-traction detection step 1702 of FIG. 17,the controller 502 detects that the wheels of the dolly 14 are moving atdifferent speeds and/or are creating yaw acceleration of the dolly 14,using a combination of wheel speed, angular acceleration, and/or linearacceleration data. If this happens while the dolly 14 is movingbackward, it would indicate that the dolly is turning. Although theremay be times that a driver intends to cause the trailers to turn whenbacking up, this intention may in some embodiments be indicated by auser input communicated to the controller 502 as vehicle data, much likevehicle data 1801 or 1901. The process illustrated in FIG. 20 assumesthat backup-assistance mode has not been deactivated by the driver toallow the trailers to turn when backing up.

If the controller detects at step 2002 that the dolly is turning (i.e.that a jack-knifing condition is present), motive rotational forceapplied to the wheels is adjusted at step 2004 much like the remedialmotive rotational force adjustments applied in stability-assistance modein FIG. 17. For example, if the dolly is turning to the right(counter-clockwise) while backing up, the motive rotational forceapplied to a right-hand-side second wheel 104 by a secondmotor-generator 108 may be increased, thereby causing the dolly 14 toexperience yaw acceleration clockwise. Other variations on motiverotational force adjustment using the motor functions and/or the brakingfunctions of the motor-generators 36 are as described above with respectto stability-assistance mode.

In one aspect, the apparatus of the disclosure provides advantages overcurrent converter dollies. For instance, in some embodiments, the activeconverter dolly 14 of the disclosure reduces fuel consumption emissionlevels. In some embodiments, the active dolly may operate to assist infulfilling a power demand (acceleration, grade ability and maximum, orhighest, cruising speed) of the tractor-trailer 10. In some embodiments,the disclosure is directed at maintaining a battery's state of charge(SOC) within a reasonable level, for self-sustaining operation wherebyno external charging is required. Also, the disclosure is directed at anactive converter dolly that may be able to harvest braking energy togenerate electricity.

It will be appreciated by those skilled in the art that variousmodifications and alterations can be made to the present inventionwithout departing from the scope of the invention as defined by theappended claims. Some of these have been suggested above and others willbe apparent to those skilled in the art. For example, although apreferred form of the present disclosure includes separate motors foreach wheel set, the present invention can also be used with a cross axleand differential in and single electrical power source, provided thesame provides enough total energy to hybridize the truck travel.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments; however the specific details are not necessarilyrequired. In other instances, well-known electrical structures andcircuits are shown in block diagram form in order not to obscure theunderstanding. For example, specific details are not provided as towhether the embodiments described herein are implemented as a softwareroutine, hardware circuit, firmware, or a combination thereof.

The steps and/or operations in the flowcharts and drawings describedherein are for purposes of example only. There may be many variations tothese steps and/or operations without departing from the teachings ofthe present disclosure. For instance, the steps may be performed in adiffering order, or steps may be added, deleted, or modified.

The coding of software for carrying out the above-described methodsdescribed for execution by a controller (or processor) of the dollyapparatus 14 or other apparatus is within the scope of a person ofordinary skill in the art having regard to the present disclosure.Machine readable code executable by one or more processors of one ormore respective devices to perform the above-described method may bestored in a machine readable medium such as the memory of the datamanager. The terms “software” and “firmware” are interchangeable withinthe present disclosure and comprise any computer program stored inmemory for execution by a processor, comprising RAM memory, ROM memory,erasable programmable ROM (EPROM) memory, electrically EPROM (EEPROM)memory, and non-volatile RAM (NVRAM) memory. The above memory types areexample only, and are thus not limiting as to the types of memory usablefor storage of a computer program.

All values and sub-ranges within disclosed ranges are also disclosed.Also, although the systems, devices and processes disclosed and shownherein may comprise a specific plurality of elements/components, thesystems, devices and assemblies may be modified to comprise additionalor fewer of such elements/components. For example, although any of theelements/components disclosed may be referenced as being singular, theembodiments disclosed herein may be modified to comprise a plurality ofsuch elements/components. The subject matter described herein intends tocover and embrace all suitable changes in technology.

Although the present disclosure is described, at least in part, in termsof methods, a person of ordinary skill in the art will understand thatthe present disclosure is also directed to the various components forperforming at least some of the aspects and features of the describedmethods, be it by way of hardware (DSPs, ASIC, or FPGAs), software or acombination thereof. Accordingly, the technical solution of the presentdisclosure may be embodied in a non-volatile or non-transitory machinereadable medium (e.g., optical disk, flash memory, etc.) having storedthereon executable instructions tangibly stored thereon that enable aprocessing device (e.g., a data manager) to execute examples of themethods disclosed herein.

The term “processor” may comprise any programmable system comprisingsystems using micro- or nano-processors/controllers, reduced instructionset circuits (RISC), application specific integrated circuits (ASICs),logic circuits, and any other circuit or processor capable of executingthe functions described herein. The term “database” may refer to eithera body of data, a relational database management system (RDBMS), or toboth. As used herein, a database may comprise any collection of datacomprising hierarchical databases, relational databases, flat filedatabases, object-relational databases, object oriented databases, andany other structured collection of records or data that is stored in acomputer system. The above examples are example only, and thus are notintended to limit in any way the definition and/or meaning of the terms“processor” or “database”.

The present disclosure may be embodied in other specific forms withoutdeparting from the subject matter of the claims. The described exampleembodiments are to be considered in all respects as being onlyillustrative and not restrictive. The present disclosure intends tocover and embrace all suitable changes in technology. The scope of thepresent disclosure is, therefore, described by the appended claimsrather than by the foregoing description. The scope of the claims shouldnot be limited by the embodiments set forth in the examples, but shouldbe given the broadest interpretation consistent with the description asa whole.

1-179. (canceled)
 180. An apparatus for releasably coupling a secondtrailer to a first trailer that is releasably coupled to a towingvehicle in a tractor-trailer vehicle configuration, the apparatuscomprising: a frame; a first trailer connector assembly for releasablycoupling the apparatus to the first trailer such that the apparatustranslates with the first trailer; a second trailer connector assemblyfor releasably coupling the apparatus to the second trailer such thatthe second trailer translates with the apparatus; a pair of wheelsrotatably coupled to the frame; an energy storing device electricallyfor storing electrical energy; a pair of motor-generators, eachmotor-generator, independently, being operably coupled to one of thewheels in the pair of wheels and to the energy storing device, such thateach motor-generator is operable in: a drive mode for applying a motiverotational force to its respective wheel; and a generator mode forapplying a regenerative braking force to its respective wheel forconverting mechanical energy generated by rotation of the wheel toelectrical energy wherein the generated electrical energy is stored onthe energy-storing device; and a controller for selectively activatingthe drive mode or the generator mode of each motor-generator.
 181. Theapparatus as claimed in claim 180, wherein: each one of the wheels,independently, includes a hub; and each motor-generator of the pair ofmotor-generators is disposed within the hub of the wheel to which it isoperably coupled.
 182. The apparatus as claimed in claim 180, whereineach of the motor-generators is independently controlled by thecontroller.
 183. The apparatus as claimed in claim 180, furthercomprising: collision avoidance sensors communicatively coupled to thecontroller, wherein the collision avoidance sensors are mounted to theapparatus or to the second trailer and configured to detect any objectswithin a threshold distance of the apparatus or the second trailer, thecontroller being configured to generate an alert when an object isdetected within the threshold distance of the apparatus or the secondtrailer.
 184. The apparatus of claim 182, further comprising: a firstwheel speed sensor operably coupled to a first wheel of the pair ofwheels for providing first wheel speed data comprising a first wheelspeed to the controller; and a second wheel speed sensor operablycoupled to a second wheel of the pair of wheels for providing secondwheel speed data comprising a second wheel speed to the controller,wherein the controller is configured to: detect a low-traction conditionbased on at least the first wheel speed data and the second wheel speeddata; and adjust the motive rotational force applied to at least one ofthe first wheel and the second wheel when the low-traction condition isdetected.
 185. The apparatus of claim 184, wherein detecting thelow-traction condition comprises detecting that a difference between thefirst wheel speed and the second wheel speed is above a predeterminedthreshold.
 186. The apparatus of claim 184, wherein adjusting the motiverotational force comprises: increasing the motive rotational forceapplied by a first motor-generator of the pair of motor-generators tothe first wheel if the controller detects a condition wherein the firstwheel speed is lower than the second wheel speed; and increasing themotive rotational force applied by a second motor-generator of the pairof motor-generators to the second wheel if the controller detects acondition wherein the second wheel speed is lower than the first wheelspeed.
 187. The apparatus of claim 184, wherein adjusting the motiverotational force comprises: reducing the motive rotational force appliedby a first motor-generator of the pair of motor-generators to the firstwheel if the controller detects that the first wheel speed is higherthan the second wheel speed; and reducing the motive rotational forceapplied by a second motor-generator of the pair of motor-generators tothe second wheel if the controller detects that the second wheel speedis higher than the first wheel speed.
 188. The apparatus of claim 184,further comprising: a gyroscope sensor attached to the frame forproviding angular acceleration data to the controller; and anaccelerometer for providing linear acceleration data to the controller,wherein: the low-traction condition is detected based at least in parton the angular acceleration data.
 189. The apparatus of claim 188,wherein detecting the low-traction condition comprises: detecting thatthe apparatus is moving forward based on the linear acceleration data;and detecting an increase in the angular acceleration of the apparatusabout a vertical axis of the apparatus based on the angular accelerationdata.
 190. The apparatus of claim 189, wherein adjusting the motiverotational force comprises: adjusting the motive rotational forceapplied by at least one motor-generator of the pair of motor-generatorsto create angular acceleration in the opposite direction of the detectedincrease in angular acceleration.
 191. The apparatus of claim 180,further comprising: a communication interface for providing vehicle datafrom the towing vehicle to the controller; wherein: the towing vehicle,the first trailer, and the second trailer collectively include aplurality of electrical systems; the releasable coupling of theapparatus to the first trailer via the first trailer connector assemblyincludes electrical connection of the pair of motor-generators and theenergy storing device to the first trailer for providing power from theenergy storing device to one or more of the first trailer and the towingvehicle; the vehicle data comprises vehicle transmission data indicatingthe state of the transmission of the towing vehicle; and the controlleris further configured to activate an anti-idling mode in response todetecting at least one of the following alternatives: the towing vehiclehas been stopped for at least a predetermined amount of time or a parkedstate of the towing vehicle based on at least the vehicle transmissiondata, the anti-idling mode comprising using the energy storing device topower one or more electrical systems selected from the plurality ofelectrical systems.
 192. The apparatus of claim 191, wherein: the towingvehicle has a manual transmission; the vehicle data further comprisesparking brake data indicating the state of a parking brake of the towingvehicle; and the parked state is detected based on at least vehicletransmission data indicating that the transmission is in a manual stateand parking brake data indicating that the parking brake is in anengaged state.
 193. The apparatus of claim 191, wherein activating theanti-idling mode further comprises sending an engine deactivationcontrol signal to the towing vehicle.
 194. The apparatus of claim 184,wherein the controller further is configured to: detect a backupjack-knifing condition based on at least the first wheel speed data andthe second wheel speed data; and adjust the speed of at least one of thefirst wheel and the second wheel when a backup jack-knifing condition isdetected.
 195. A method for providing stability assistance to aconverter dolly towing a second trailer behind a first trailer, thefirst trailer being towed by a towing vehicle, the converter dollycomprising: at least a first wheel rotatably coupled to a left side ofthe converter dolly and a second wheel rotatably coupled to a right sideof the converter dolly, the first wheel being operably coupled to afirst motor-generator, the second wheel being operably coupled to asecond motor-generator, such that the first motor-generator and secondmotor-generator are each, independently, operable in: (i) a drive modefor applying a motive rotational force to the respective first wheel orsecond wheel; and (ii) a generator mode for applying a regenerativebraking force to the respective first wheel or second wheel forconverting kinetic energy generated by rotation of the respective firstwheel or second wheel the electrical energy, the regenerative brakingforce effecting deceleration of the respective first wheel or secondwheel; the method comprising: detecting a low-traction condition basedon at least a rotational speed of the first wheel and a rotational speedof the second wheel; and adjusting one or more of the motive rotationalforce and the regenerative braking force applied to at least one of thefirst wheel and the second wheel when a low-traction condition isdetected.
 196. The method of claim 195, wherein the firstmotor-generator and the second motor-generator are controlledindependently.
 197. The method of claim 195, wherein detecting alow-traction condition comprises detecting that a difference between therotational speed of the first wheel and the rotational speed of thesecond wheel is above a predetermined threshold.
 198. The method ofclaim 196, wherein adjusting the motive rotational force comprises:increasing the motive rotational force applied by the firstmotor-generator to the first wheel if the rotational speed of the firstwheel is lower than the rotational speed of the second wheel; andincreasing the motive rotational force applied by the secondmotor-generator to the second wheel if the rotational speed of thesecond wheel is lower than the rotational speed of the first wheel. 199.The method of claim 195, wherein the low-traction condition is detectedbased at least in part on detecting an angular acceleration of theapparatus.